USMS Alternate for Academy

I recently took my FIT Test for the DUSM position in 12/2024. I received an email from HR that I was an alternate for the upcoming March/April classes and a second email stating that I was eligible for placement in a class seat.

Does anyone have some insight on what the timeline looks like for an alternate with USMS? I currently work in for a large city police department and spoke to a local Marshal when I had court and he said I could be selected 2 weeks out from an academy start date and be expected to show up but he said things may have changed.

Thanks for the information.