Freedom Flex AU Card Numbers

Yesterday, I PC'd my OG Freedom to a second Freedom Flex for the upcoming 7x on dining. This morning I saw that card tracking was available on the new account and it has a different last four card numbers for me and for my P2.

Looks like Chase may have started using separate card numbers for different users like they did on CSR. Anyone else recently PC or open a new Chase account and notice this on non-CSR accounts?

Or have I been under a rock and this has been the case for at least a little while? My last new Chase account is like 13 months old and we had the same card numbers on that one.

Update: Received new cards today. Main card and AU card have different last 4 numbers. Both cards are the new MasterCard and are under the same account. This is not me saying the MasterCard numbers are different than the Visa one. I am well aware I was getting a new account number. This is to say the main card and AU card have separate card numbers.