I actually found this worrying, since it means they are not committed to make NextJS work nicely, quite the opposite they now have incentive to not make it happen
The NextJS team should be working on making NextJS run better with Deno, not the other way around. If the NextJS team doesn't want to do the heavy lifting with that support, thats on them. I think its perfectly reasonable that the Deno folks have an approximate alternative to NextJS. After all, NextJS won't use native Deno idioms for example, it'll always be tied to Vercels' proprietary cloud infrastructure.