I'm certain it will be released for Switch, just not anytime this year most likely.

Activision are the ones publishing Spyro Reignited and they're also the publishers behind the new Crash Bandicoot N. Sane Trilogy for Switch. So I think it's safe to assume they have the same plans for Spyro.

Most likely just so they have a steady line of revenue, get everyone to buy Bandicoot while it's hyped then have them do the same a few months down the line for Spyro. Also prevents the two games from competing with one another.