This is a way of sucking you back in.
My brother, who lives in Australia, did this repeatedly with my mother.
Arranging for something that I had to follow through on because he "couldn't be there"
but it meant more work and involvement for me with him getting off guilt-free.
Don't buy in.
If you don't want to get back on the enabling crazy train, stand your ground.
Sister L walked away for 2.5 years. Tell her to call you again in that amount of time.
Nothing changes if nothing changes.