Back in 2015, it was on legacy MOL- but sometime during 2016/2017, it was removed and only added if you opened a case. Last version was R20.50.10. You will need an F/W upgrade refresh key to properly upgrade the codeplug in addition to the firmware. Since these are department radios, this should be done properly and not the hacker/whacker method.
Good luck getting support from MSI. I haven't seen Astro 25 CPS on our MyView ever. It is out there, both CPS and firmware. The hard part would be finding that F/W refresh key. What version HOST are your 2500s at now?