The finale was so good! I was not expecting that much content.
Honestly, if they don't make Braven become romantically involved, I do at least want to see flashbacks of how they rely on each other as friends and just their bond on that level. Don't get me wrong, I can see the writers pairing up Becho on the Ark, but Raven and Bellamy established at least a close friendship that could only develop further on the Ark. The fact that it's the two of them at the end scene on the Ark and not Bellamy with Echo or even Bellamy with Murphy or anything says a lot. I feel like there is setup there for them to develop romantic Braven. However, as many have said here and on other sites, I do not want them to develop Braven romantically if they were to push Raven aside as soon as they land to make Bellarke canon. That would be a rehash of Raven/Finn/Clarke, and as much as I'm pleased that both Clarke and Raven realized they were too good for Finn and both dropped him like a hot potato, I would be hesitant to think that the writers would pass up a cliche love triangle for a second time.
And if they did have Bellamy and Raven break up for Bellarke to be canon, that wouldn't be fair to either ship, nor any of the three characters, nor to either set of shippers.
So... if they do make Braven canon... they either need to keep it canon... or if they have them break up, do so in a way that is natural and takes time and respects the ship for what it was even if Bellamy gets together with Clarke.