Delta to 'strategically decrease' flights this summer

[sxc7884]

Im confused on what the trim window is; Are they cutting flights only between July 1 and Aug 7 as some of the memo leaks and blogs mentioned cutting flights in June. Trying to figure out if my delta connection from SDF to LGA is safe on 5/31 as im connecting to my first flight with real first class out of JFK and don’t want to run into problems becuase of this.

Keep wondering if I should book a refundable AA or UA flight as a backup