H1B Transfer, h4 extension with new employer, what will happen to my spouse's H4 Extn if I am unable to join new employer?

Hi All & @anil_am22 ,
My name is Seema, I need your kind suggestion. I am working with Employer A and my husband is on H4/EAD (with my Employer A). Employer B is planning to do an H1B Transfer/H4 Extn concurrently for us. So let’s say Employer B files H1 Transfer + H4 Extn concurrently, and after H1B transfer is approved, I decide not to join Employer B as I may have to travel because my dad is not well and have continuous sickness and covid symptoms, then what will happen to my husband’s H4 Extn which Employer B has filed concurrently? Will, it gets auto cancel his H4 Extn request (via employee B) as well, or do we need to do anything extra in order to stop/Cancel it? Will it have any impact/issue on his current H4. Just don’t want to take any unseen risk.