Stealing your top comment (sorry XD) just to answer OP and anyone else who, like me, despise this shit decision made by meta.

Here's the deal:

this feature is only available in some of the home environments, those being: Desert Terrace, Space Station, Winter Lodge, Cascadia. In those environments, you're now able to walk around it too, if that interests you. But unfortunately, there's no way to disable this, so if any of these environments were your favorite, I'm sorry but you'll have to pick another one to disable this shit.

I was using my Quest all night and this wasn't there, then all of a sudden I decide to use it now and have to deal with this shit. Seriously, if this comes to all environments, I'll find an alternative app to replace it. These avatar are REALLY poorly made. They should be ashamed to release such an awful update that literally NO ONE asked for.