UPDATE: This information was false as the source I received the info from was not confirmed with an authoritative source on the subject (the previous info came in bits and pieces from one of my friends from school who’s also into sirens).
Here's the new info (thanks to Thomas (SRP) for helping me to get the mystery solved and for letting me know so I could clarify and confirm it):
They still test first Saturday everywhere but recently implemented a new policy that doesn't allow them to test till after the SWA Tornado Drill!
The SWA Drill will be the first test of the year, and Saturday, April 7 will be the first regularly scheduled monthly test (which will be happening the first Saturday at noon). I’m pretty sure the alert/attack cycles for Independence will be the same as it was before. As for the other cities they will probably run in Alert as they previously did. For whatever reason, I guess they decided to stop testing in the winter, which is the first time they’ve done this, but it is probably because cold weather is hard on very old CD era mechanical sirens.
Therefore, the information above is incorrect. Yes, incorrect. If I can delete the above post or edit it to redact the false information I will do as ASAP so as to not cause confusion.