Completely disagree.
Alternate timelines are portrayed very specificity in Trek as being traceable Tom a specific temporal event, like the Nero incursion, the Yeaterday's Enterprise Time nomoly, or McCoys screw-up in the 1930s. They typically depict a different version of the present
Possible futures are portrayed as just that, without any specific point to say "this is what caused everything to go in this direction".
There's a substantial difference. One is speculative bullshit. The other is not.