There's a point here, but that's not just because a phone is a flagship. All of this depends on the business model a manufacturer chooses to follow.
If Flash is really out of Alcatel's reach and acting as a separate entity, Flash would be able to make phones not deemed to be a Flagship but can still provide updates, though a lot of resources needs to be given into R&D.
So who would fund the R&D? It goes down to how the phones were taken by the target market.
Just hope that Flash, as a community, will welcome XDA developers to enhance the community and cut any cost of providing updates on their own if they'll be able to work it out with known or established developers that are willing to play around the Flash phones.
Since, supposedly, Google CTS would require Vulkan API compatibility for the build, our AF2 which has Mali-T720 won't have N - officially.