It’s now mid-February, so the last stragglers holding on to their 1998-2003 plates have had to give them up. New letters are now up to CBE. With the replacement cycle, Iowa currently doesn’t have any active combinations from that sequence up through somewhere in the N’s (issued in 2004, and being replaced this year).
For standard-issue Iowa license plates, that means the stamped, raised-letter era has passed, replaced by screen-printed, thinner-metal pieces. However, to my knowledge there has not been any concentrated effort or policy to replace 10-year-old-plus REAP, college, or government license plates. (The latter are black-on-white, used on school buses, fire engines and other municipal vehicles.)
The state should probably get on that, as those plates have the same wear and tear issues as the others, but replacing them could be tricky because of the different letter-number patterns.