There have been numerous leaks indicating a ram and compute bump internally. The og switch is old, and was underpowered when it launched. The switch 1 derivatives (think like the OLED variant) had comparably powered internals as the launch model.

You are correct that nothing has been advertised about the specs, but these are leakers with a good track record, and it stands to reason that Nintendo would want to have modern hardware on the market to make porting and development more attractive prospects for developers. They also have a history of re-selling old content through online e-shops that rarely (if ever?) persist through generations.

Everything definitely lines up with this being a significant hardware change to ensure future revenue streams exist for Nintendo.