The Switch will be fine.
Development takes time. Third-parties did not know if the Switch would be a success. So here we are. If their games work on the platform, they'll get onboard.
Most publishers had also adjusted their strategy away from handhelds, so it wasn't like they felt compelled to get on board the instant the Switch released to continue on their business lines.
If your focus is on pumping out mobile games aimed at Japan and console titles aimed at a global audience, and then you have some cheaper licensed Vita/PS4 games that sell to fans of whatever anime is on this season, it's not exactly an emergency to get on board the way it was for Western console publishers to prove consoles could still do well in the West back in 2013.