Well, those are a lot of assumptions and interpretations. Fans have the tendency to take things, facts or rumors to fit a narrative, which is also reflected in how they arbitrary select what to believe and what not from official statements or interviews we get, either from Britney or the people she collaborates with.
We don't know why Original Doll was scrapped, the demos we've gotten sound very unfinished and really most of them aren't that good. She could've perfectly rescued that project and release it instead of Blackout, but a lot of time had passed in between, so it didn't make sense. And before that, she had her two babies, so if she released it in 2005 or 2006, it would've been paid dust and hated by the fans for being the least successful album.
Fans tend to overrate her involvement in Blackout too, as if she was the mastermind behind the style or lyrical content, when the very same people that have worked on it, like Danja etc have already said she just came to the studio and recorded whatever they had already worked on beforehand, and leave, which is basically what she's done in every subsequent album. The only sort of direction she had was according to Danja, you would know when she liked or didn't like a particular song, which again, coincides with what she's stated for other albums too, that she only records the songs she likes (despite fans having this misconception of Britney being forced by her team or label to record stuff she hates with her heart).
About Circus being demos that Britney did, or that were supposed to be from previous albums, I don't know where that info came from, I've only read it here on Exhale since last year, before that I had never come across it, so I can't tell whether it's true or not, but it doesn't make a lot of sense to me. It's clear though, that this was her father and Larry's, and Britney's attempt to prove the public that she wasn't a mess anymore, that she could be the pop girl we all loved again, and that's why they brought Max Martin, Danja, Guy Sigsworth, Bloodshy & Avant, etc to make the ultimate Britney album, and worked with people like Francis Lawrence and Joseph Kahn.
With Femme Fatale is when the rumors about the album changing direction start. I think it's really tricky because we don't have lots of interviews or like a documentary that details the early process of all these albums. Again, people always jump to the worst conclusion: her team forcing her to do stuff she hates, because they love see her suffer. But how do we know that maybe Britney really liked the later stuff more than the things she records in the beginning stages? She always says she wants something more urban, how do any of us know what her concept of urban is to begin with? She herself has described her songs in weird ways, like when she said Pretty Girls was a song for the clubs, or when she choreographed a song like Make Me... but Alien which was way more danceable was performed sitting on a chair.
I digress, what I wanted to say is her latest albums have taken a while to make, unlike Oops which was made in just a few weeks. So in all that time, she can change her mind multiple times. Maybe she did like all the material, but they can only pick a certain amount of songs for the album (they could actually pick as many songs as they wanted to, but whatevs). Britney herself has said she's the one who decides which songs make the album, but again, here's where fans would arbitrarily choose to believe her or not to fit a narrative. She specifically expressed very well about working with Dr. Luke and Max Martin for Femme Fatale, and what she said is she wanted something different from her previous record, and it IS different.
For Britney Jean it was different, again, in the very beginning she said it would be more urban, but this was even before will.i.am was named the producer. She may be recording stuff all the time, but that doesn't mean that she's always intending for all the material to make it to an album. The declarations we did get from will.i.am and Larry, which again, probably most fans won't believe or will ignore, is that Britney didn't want to deal with picking the songs submitted from the various songwriters and instead will worked as this sort of filter. will himself spoke about club bangers or super heavy beats that came to him, without naming anyone in particular, but Danja comes to mind, and saying HE didn't think they fit the vibe from the months of conversations he had with Britney prior to the recording process. Yet songs like Tik Tik Boom or Body Ache made the record, but maybe Britney did like those, so who knows.
With Glory is the only one where we have a "clearer" timeline or indication that the album did change direction and that's when Karen came in, yet we still have songs from 2014 in the record. Also, Britney didn't mention a change in her record deal, but she spoke about the conservatorship instead at Jonathan's show. Which in itself was a weird statement, not only because she allegedly mentioned the conservatorship having existed for only 3 years (which could've been a brain fart due to nervousness) but because she mentioned like in the past not having a lot of control due to it, but now being able to do more, as if the conservatorship didn't exist anymore or an important shift happened with it, when we all know nothing has changed (at least back in 2016). What I mean is, it doesn't really make a lot of sense why she was allowed to do more, allegedly, for Glory than the previous records, when the conservatorship was still the same.