L2(with extension receipt) to H4 Status Change

I am on L1 Visa, I94 got expired on May21, submitted for extension, waiting for results and this is same with L2 dependents. Now, I got H1B sponsored from another company and it got approved with COS with effect from oct 1st 2021. So now L1 status got changed to H1 from oct 1st.

Q1.What happens to L2 so do we need to apply for a status change from L2 to H4 before getting l2 extension results or need to withdraw the extension and then apply for l2 to H2 status change. And will there be any issues in future, like on which status the dependents stayed in the US for four months
Q2. What happens to my L1 extension and meanwhile if it gets approved?

Ideally you should have applied for L2 to H4 COS when you applied L1 to H1B COS. The L2 EOS may get denied as the primary L1 has already changed the status to H1B effective 1st Oct. Even if it is approved till the date requested in the EOS petition, their L2 status will automatically expire on 30th September as the primary changed the status effective 1st October.

You can consult your immigration lawyer and have them apply for change of status from L2 to H4 using NPT so that any gap from when the L2 will gets denied (or if approved the L2 status will auto-expire on 30th September, which has passed already) can be covered.

It should get approved as your change of status from L1 to H1B was approved already. If it gets approved per the date requested on the extension application, it should have no impact of your current H1B status.