Ebony Maw wasn't in a "full vacuum" right away either. And he demonstrated the use of telekinesis at blinding speeds in battle, so why not then? If he could throw cars around, why couldn't he move his own body back into the ship?
Also I just looked it up and the "speed of spaceship decompression" is NOT that fast when you have a huge room and a comparatively small breech. Not if you're standing as far away from the breach as Ebony Maw was.
And even if you ignore those physics, and pretend there was some weird rule to his magic that it could be used to move himself only really slowly when he can move everything else fast....then why not move a bunch of oxygen from the ship into a little orbit around his body? Heck, a huge amount of air from the ship was just sitting out there in space. He could telekinesis his own atmosphere if he wanted to. Or move part of the ship to him to rescue him.
Gamora was out in space a long-ass time and didn't appear to suffer any lasting effects. It seemed like they were saying that oxygen is all she needed to stay alive. Okay then, why didn't Ebony Maw have 60-90 seconds to work with before he ran out of breath?
Quill was out there for damn near a minute without even oxygen as was still functioning. And whatever his Celestial life-saving powers were, they weren't strong enough for him or anyone else in his entire life to have the slightest clue that he had any powers at all, so I'm not buying that excuse.
Thor not only moved around in space but was even talking, so coming up with air out of nowhere seems to be a thing in the MCU.
And it was amusing that the speed of spaceship decompression was so impossible for Ebony Maw to overcome with the powers that he's had use of for years, but teenage spiderman had enough time to deploy the spidey legs on the suit that he had just put on for the first time minutes earlier with no instructions. And nice delays on the decompression affecting everyone completely differently.
