My then 7 year old had zero gymnastics/cheer/minimal dance and was picked up on team after 6 months in rec. I don't think it's that odd.
That's not odd, but a 6 year old entering at level 3 with not much experience is questionable unless they are phenomenal. I have a 6 yr old who's been in gym since 18 months, and she was invited to level 1, her 6 yr old pre-team friend went to level 2, but that young on 3 without competing 1 or 2 or just a super talent doesn't happen at our gym. The gym is extremely successful at every level, and I've had other daughters go through, up to Lvl 10, I've been around a long time. I can spot the talent almost as well as the coaches and owners, and have predicted new class-to-team kids with almost uncanny accuracy. I don't think it's odd at all, just the age and level with the minimal experience. That's why I questioned.
Some gyms put girls on higher levels who aren't ready for that level because they can perform a skill from that level even though all the other skills aren't there. I've heard of it and I've seen it.