Yugioh question: GB Bestari/Gyzarus vs TT/BTH?

Question

GB Bestari or Gyzarus is summoned and priority is called so using their effect destroying a spell or trap card on the opponent's field.

If the spell or trap card is TT/BTH can that card be activated?

Someone said it couldn't because the timing is off for the activation since TT//BTH is chaining to the monster's effect and not the summoning of the monster.

Answer 1

Yes, you can.

Lets just look at Gyzarus:

Gyzarus successfully summoned(Does not create chain)

Priority MUST be called to activate effect->Bottomless Trap Hole then could activate.

Solve the chain backwards:

Bottomless Trap Hole activates, since the summoning of Gyzarus is the last thing that happened, Gyzarus is removed from play.

Then you use Gyzarus effect.

Who the h**l told you that you cannot chain to that?