I have no clue where 4" Star Wars is going. I feel like they're devoting more to the 6" line, as far as collector-targeted stuff goes. Maybe it just feels that way, but damn near every wave is chock full of new tooling so I'm reluctant to say they aren't leaning that way.
I don't know that 4" would go away, so much as 4" collector toys would, and 4" would be all the cartoony and 5 POA stuff, which has customizing potential only to me, and I'd never shell out extra for any of it. If that were to happen I'd be very much dedicated to other things I collect, mostly out of Japan at this point, which would suit me just fine I think. Acid Rain would also get booku $ from me going forward, haha. I actually may even "army build" some of the vehicles! Hell, that thought alone almost makes me wish Hasbro would bail on collector 4" stuff I wanted, hehe.
I don't think they'd can 4" all together though. I lean against that thought. I just feel like 4" could be the kid's line, movie/cartoon focused obviously, and 6" will be a mix of old and new, very collector focused, and perhaps it would flourish with more interesting things like larger accessories, smaller vehicles.
I will say, the MASK news that's out there really is surprising. Yet another direction they're going? Is this where Joe's budget went?