It's a question of installed base and margins. First, like for any new console, the strategy is to push consoles sales in the first 2 years of the lifecycle, in order to expand the install base as fast possible. read more
Lets skip past the games where the original publisher doesn’t exsit anymore, the games which the developer doesn’t want re-releasing (e.g. the SNES Mortal Kombat ports), or the now publisher wants to release it themselves and make more money than letting Nintendo do it. read more
Rather, it looks like Nintendo will opt to trickle its arsenal of classics down to the Switch – we’d wager that most of the better known NES and SNES games were available within a year or so of launch. read more