It is certain that the group from 'Revenant' did not become standard borg - their behaviour is significantly different from the main collective's.
Of course, they did not remain "basically the same as they were, psychologically, only united in the mini-collective, without wanting to assimilate anyone further".
They still felt that hunger.
But it's also true that their main objective (which appears to be even above assimilation) - revenge - would be instantly qualified as 'irrelevant' by the main collective.
And their unusually pacifist behaviour from the end is further proof of their uniqueness.
In my opinion, making this mini-branch of the collective exhibit a behaviour different from the borg proper (perhaps more ambiguous, morally-wise, than the pitch-black borg) has much more potential - essentially, is more interesting - story-wise.