I mean, at least in Germany, the law currently prohibits larger gatherings. I think it would still be illegal, even if everyone were in a giant bubble. It would be very dangerous, too. People could suffocate or get stuck. They might fall or even roll down a slope and hurt themselves. The bubbles might not be strong or air tight enough. It's a pretty bad idea. However, it is fun to imagine. Let's all have a bubble party in our minds.

Panel 1:
The descent into madness continues...
H: Oh man, I never wanted to have a party that badly.
Panel 2:
G: I know what you mean...
Wait! What if we got everyone those giant hamster-ball kinda things? Couldn’t we just...
Panel 3:
G and H, along with many other people, have gathered. Everyone is in a giant hamster ball.
G: See? A perfectly safe combination of quarantine, mosh pit and bouncy castle. Best. Idea. Ever. Ahem ... did you just fart?