I am wondering how strictly they enforce this. Just asking.
Nope
Nope. Considering receive times you are well past the cutoff.
Yes, some sellers still try to send in chocolate close to or after the April 15th meltable cutoff, but it’s definitely risky because Amazon does enforce this policy quite strictly in most cases. If you send meltable inventory after the cutoff, Amazon may reject the shipment, dispose of the units, or even flag your account for policy violations. The safest approach is to either pause sending those SKUs until the window opens again in the fall or consider selling them FBM if you have the means to control the storage and shipping conditions yourself.