New Version - what about Team Systems list?

Hello together,
in the News for the new Version I found that statement:
"The Teams system list is deprecated and should not be used. If you need a UDF for a list of teams, create a UDF of type Team that points to all available teams defined for the workspace."
Can anybody help me understand what I have to take care of?
 
You can find it here: 

What's new in 15.1.60 under "Licenses"

Thank you and best regards
Georg