In the short term, it's a detriment; they will have to struggle more and will encounter more difficulties in socialization. But that's not necessarily a Unique problem, there have always been kids with these kinds of problems, if not at this rate. And on this short term we're decreasing mortality from covid and hopefully keeping hospital resources available to minimize mortality from other causes.
Over the long term, decreased mortality is generally a net societal gain. An increase of people with issues socializing will result in an increase in the market for solutions, tools, community, and support that help with this kind of problem. These solutions would help both the pandemic babies And those who would normally struggle, and would be available to future generations too!