ACDelco is shifting their naming strategy with filters.
Historically, filters with an "E" at the end were E-cores and those without were not.
PF48E = E-core
PF48 = Not an-E-core
That is changing and the "E" is being dropped across the filter line. There will just be a PF48 now and it will be an E-core. You can identify the change by the new-style ACDelco box that's mostly white (instead of blue) and has the "Genuine GM OE Original Equipment" logo. I believe the 8-digit P/N changed as well and is not the same as the old PF48 or PF48E.
UPF48R is the "racing" version of the PF48. It is and always has been a non-E-core filter.
Double checked the 8-digit P/Ns:
Old PF48 non-E-core = 89017524
Old PF48E E-core = 12690386
New PF48 E-core = 12710960
I'm sure it'll take a while for the retail supply chain to catch up, so you'll likely see some mish-mash of them on shelves together.