Oh, OK.
I misunderstood it.
I thought it was about ARC holders trying to entry Taiwan to reunite their families (who I supposed were already here). But it is in fact ARC holders already here trying to bring their relatives to Taiwan.
Got it, now. Thanks.
Nope, ARC holders can come back to Taiwan. Just the spouse and children currently are not allowed to enter Taiwan yet due to Covid-19 measures taken. The dependent visa for ARC holders has been suspended since May 2021.