no. many folks have requested this functionality, but the infrastructure (and cost) needed to process and host a lot of video probably is beyond what a small organization like iNaturalist is realistically capable of taking on. some folks post animated GIFs, but this is not true video (which would include sound), doesn’t display correctly in all iNat interfaces, and is frowned upon though not punished by the iNat overseers.
for now, you can post your videos elsewhere and just link to those in your observation, like i’ve done in the description of this observation: https://www.inaturalist.org/observations/157901323.