Old logo was probably the cleverest rendering of a fox using very few lines. The new logo is a lot less smart, much more standard. Typography is also uninspiring: seems to be using Inter, which is designed to not have any character (pun not intended). Although, to be fair, old logo also had very basic typography.
The GitLab logo/mascot is actually a tanuki, a Japanese racoon dog. It symbolizes our values as a smart animal that works in a group to achieve a common goal.
Didn't know about this animal, pretty cool.