Why people think it doesn't work with sneak attack any more? Any specific reason?

From the picture we can see words like "brandish weapon" and "hit".
Sneak attack just requires an attack with a finesse weapon.

Warcaster and twin are probably out unless there is specific wording for these cases (which is unlikely), but not SA.

And also no, rogue doesn't need it, but it's nice on melee rogues as a risk/reward play. After all going warcaster for BB isn't such a hot pick on rogue. Enemies would rather hit him than flee. All that went away is the MI + Warcaster + Sentinel interaction which again was inefficient. Just MI+Sentinel is enough.

Also there is a thread with leaks on reddit and it seems that rogue got a new cunning action that gives advantage on the next attack which is a substantial buff in rogue's reliability.