Can Watch OS 5 beta be reverted back?

It has never been possible - there is no mechanism to reinstall an older software version.

If in doubt, wait for a couple more beta cycles before installing

I see Apple has pulled WatchOS5 from the download page to investigate lockups on some Series 2 Watches. I'm just wondering why there is no downgrade capability like there is for their other devices. Maybe something to do with the wifi consumer interface and a need for using the hidden port for a reflash? Anyone know?

Last year when the beta went haywire Apple had me send them my watch and the re-imaged it... took a few days.

I've noticed that Beta5 has had a ton of problems on my Series 2, it keeps wanting to update, but can't find the watch anymore.. I knew this summer's betas were going too well.