IIRC there is an intranasal expected to be approved mid next year. I can't find the source I read that in, so take the timing with a grain of salt. Another source I can't find at the moment mentioned questions about the duration of protection from that method of vaccination as well.

I would guess the push for intramuscular was driven for multiple reasons, the first being ease of development and the second to keep hospitalizations and death at a minimum.