For any tea leaf readers, I looked at the 2020-2021 cycle which was also administered by SysPlus, and they crowdsourced a Google spreadsheet of the updates.
https://forum.thegradcafe.com/topic/126090-ndseg-2020-20201/?do=findComment&comment=1058825232
(direct link: https://docs.google.com/spreadsheets/d/1qBzKN6fLLH11WsgaoQnfcC4aECeBOOXvc8FTxhs9qfc/edit#gid=466934317)
From the 3rd sheet, 14 users reported receiving March updates, 10/11 of those ended up receiving the fellowship. 3 or 4 of those were waitlisted. From the 1st sheet, 7 users reported receiving March updates, 4/5 of those ended up receiving the fellowship, 2 did not say.
Some selected fellows did not receive a February update.
Emails were sent 3/29, but many confusing updates were posted to the system in the preceding days.