Hmmm. Very odd, but probably a VERY nice move by Trump, relationally, for the Bushes, as well as the address of the increased security complications. Look, I mean they despise him.
The Bushes will greatly appreciate the First Lady and will be pleased to have her. Trump otoh, displays the personal consideration to back away, for a couple of very good reasons.
God bless FLOTUS. Lord please keep her from all evil.