In my own opinion, I think Quint's involvement in the past would give Megaman ample warning, and thus prevent his current timeline from leading to the events that cause him to become Quint.
Well, it does kind of make sense, what you are saying.
Bur our blue bomber could be always taken by surprise. It is possible.
Also, take into account how time travel works. If Quint who is Rockman from the future, appeared before Rockman from the past, it would mean that Quint(while still being Rockman) also met himself from the future, at one point in the past.
As long as you do not inflict a Time Paradox, upon the timeline, it just means that the "future you" you met, also once met himself from the future.
Unless we'll go with "Each Time Travel creates an alternate universe" thing. Then probably Quint never met himself from the future.
Jesus. I think I'm overthinking this a bit... oh what the hell. Why not?