First thing I saw was the colouring. This design has mostly focused on colouring, icons, and bottom bar.

It has introduced changes in terms of aesthetics:
- The Chat List looks quite beautiful: the colours are good looking together
- The blue background clearly highlights the chats with white background
- Blue divider as a result of blue background is nice-looking

Some disadvantages:
- The online circle icon could have been placed at the right bottom of pfp on chat list.
- It would be better if chats icon for the bottom navigation bar was in the middle, not in the right.

The designer has focused mainly on blue colour to reflect the app colour. The redesign introduces vast colour changes by leaving old style. I can see that the icons were chosen with care.

Good luck, this design does not deserve negative overall either