No it couldn't? A lot of (most?) threadmills have something below the underside of the belt so that objects can't get sucked in.
Also, for all I know, it's possible that those threadmills have some safety properties which the Peloton threadmills don't. Is the belt less grippy, so that it would be easier to get out? Do the motors stop spinning when they get stuck? I don't know, but it doesn't seem too unlikely. I'd be interested to know.