Martok said:
Actually both.
If the summoned monster doesn't have 1400 ATK or less while the game state says "a summon occurred", Wanghu's effect doesn't activate. And at resolution, Wanghu's effect will only kill monsters with 1400 ATK or less.
Likewise, BTH can only be activated as a response if the summoned monster has 1500 ATK or more. And at resolution, BTH will only remove monsters with 1500 ATK or more.
"Trap Hole", yes, definitely, but you can't say for certain that it applies to Bottomless Trap Hole.
Bottomless Trap Hole is non-targetting, and there was a ruling in the opposite situation that suggested it doesn't work the way Trap Hole does.
Old Ruling:
Summon monster (1500+ ATK)
Activate Bottomless Trap Hole
Chain Call of the Haunted (to Summon 1500+ ATK)
Bottomless resolves to destroy and remove both monsters.
Suggesting that once Bottomless Trap Hole activates, it only checks as it resolves and throughout,
Now although the ruling is changed, it doesn't eliminate the mechanic of adding a new monster to destroy; it only eliminates the possiblity of destroying a monster not summoned at the same time:
So for example:
Special Summon 2 monsters with Return From the DIfferent Dimension, perhaps Gemini Elf and Don Zaloog.
Activate Bottomless Trap HOle
Chain Rush Recklessly (Target Don Zaloog)
It's likely that bottomless trap hole can destroy DOn Zaloog in this situation.
Now Bottomless Trap Hole is a card where the player decides to respond to a summon, King Tiger Wanghu is an automatic effect, and thus is likely to be ruled different. The default is as mentioned on the FAQ is that conditions only need to be correct at activation, but the ATK value consideration likely makes it an exception as bottomless trap hole.
It'll likely only concern itself with the ATK at activation at all, or once its legally activated only concern itself with the ATK at resolution, not both.
The card activation and eligibility about "Trap Hole" is likely not going to apply in the end, but is the most certain answer providable as there's nothing conclusively to decide between the other 2 possibilities.