Earlier this fall, I received a notice that my credit limit had been reduced by a few hundred dollars. I called and asked why, and the bank couldn’t explain.
I then called them back and requested a credit increase. By the end of that day, they increased my credit limit by more than I had requested.
The total credit limit increase they gave me was 50% more than my previous credit limit before they tried to decrease it.
FWIW.
Personally I think the reason the limits are being reduced is so people can hit their credit limits easier and pay more money in over-the-limit fees.
I haven't received any notices and don't really expect to - I only use one credit card as a convenience for groceries/gas/dinners, etc., and always pay it off each month. I'll make a guess that those who use their cards to overextend themselves will end up being forced to wait until they can pay for things due to lower credit limits.