It's a possibility but pivoting to software isn't easy by any stretch, and it wasn't something Sega should have even been able to do (financially.) The only reason it happened is because Sega's biggest debtor, Isao Okawa, forgave that debt on his deathbed.
In a slightly altered timeline where Okawa didn't do this, Sega would have went under and its IP's would have been sold piecemeal to the highest bidders.
Nintendo has famously large cash reserves rich and a quick Internet search suggests they have about 7 billion in cash. Things would have to go very badly for them to go out of business, especially as they can presumably issue new stock to help raise money for a pivot in some sort of doomsday scenario.
