a list of upcoming tier 10 discounts was posted on Reddit, the source being the calendar itself, where it is designated for the American server. Future tier 10 discounts will be as follows:
Object 140 (March 31st – April 14th)
WT auf E100 (April 14th – April 28th)
B-C 155 58 (April 28th – May 12th)
I do NOT think that this list is valid for other servers however, each server handles this discount independently. It might match, but it doesn’t have to.