No it's corny no matter what way you do it, it isn't happening.
(Thank Christ for that.)
And for the hundredth millionth time this isn't a retcon, A3 isn't being erased but it is being ignored which equates to an alternate timeline-
I don't get what's so difficult to (accept &) understand about this.
Are you serious? What differentiates a RETCON from an ALTERNATE TIMELINE?
There are still multiple reports on a regular basis that provide conflicting info. Blomkamp's words say "I get the opportunity to fill in the gap" and "I'm not trying to undo 3 and 4"... You taking that confusion and creating some difference between a retcon and an alternate timeline is odd. There is no difference, unless Fox were to literally try and destroy all future copies of ALien3 ... Is that what you think constitutes a retcon? A retcon implies an alternate timeline. Its the same thing.
Now, unless I've dreamed this stuff myself - over the years, fans, like Blomkamp, who dislike the third film have been going on and on (for decades now) about how something else has to have happened to get the egg on the sulaco - so it doesn't seem in the least bit strange to suggest that he intends to make his film that something, apart from the age difference which has been accounted for by much lesser franchises like TRON in the past.
Do I pretend to KNOW this is what is happening? NO.
But neither do you and your assertion that an ALTERNATE TIMELINE is somehow not implied by a retcon is just bizarre.
A retcon automatically creates an alternate timeline.