Hi Jeroen van der Laan,
Yes, you can use the MC33PF3000A5ES and the MC34PF3000A5EP interchangeable replacements for the MC32PF3000A5EP. I would recommend the MC34PF3000A5EP (Industrial), because it shares the same package as the MC32PF3000A5EP (consumer), while the MC33PF3000A5ES (automotive) have a little different package (wettable flank).
Maybe the reason why you cannot find them in the product selector when i.MX6SX is selected, is because A5 programmed version is for the i.MX6SL as you can see in table 1 of the PF3000 datasheet: https://www.nxp.com/docs/en/data-sheet/PF3000.pdf
Programmed versions A3 and A4 are made for i.MX6SX.
Regards,
Jose