I have thought about this quite a bit and talked to my kid about it.
I think it depends what you mean by competitive advantage (will come back to this.)
Lets say this ultimately ends up being a year (March 2020 - March 2021).
So for a year, kids where they didn't shut down got to play more. And the kids out here haven't been totally shut down. Depending on your club and tolerance they still have been able to play quite a bit....but definitely a significant amount less.
Lets say that it was an all clear in April, and then you ran a big national tournament immediately. No doubt, the teams from CA would not do as well as those that had been playing fully during the shutdown (although the CA teams are generally better, so they would still likely win a lot.) I would submit that within 3 months of the re-start, this dip in competitiveness from the CA teams would be corrected.
So back to the competitive advantage argument that I have heard a lot of people make. Yes, in the short-term, there will be some catching up to do.
Beyond that, it is totally insignificant. If you are talking about being able to play at a top D1 program (you brought up college in your post) - this break will have absolutely nothing to do with it.
Those athletes have characteristics that have nothing to do with playing a bit less over a year. They are more characterized by soccer IQ, speed, strength, natural soccer skill, mental and physical toughness, etc. Yes - they may have a little more rust - but if they have these attributes, they will have the ability to play at a top school.
If they do not have these attributes, no amount of extra training or game play that they missed during the more strict lockdown in CA is going to help them gain a competitive advantage.
So yes, maybe the kids in Omaha were able to keep playing....but it won't magically make them more competitive.