As with most of the best trading card games, the Pokmon TCG uses set 'formats' - separate, standardized modes of play - to keep the game fair and balanced, and ensure the game experience stays fresh and interesting, without just one or two over-powered cards or decks dominating every tournament
If I were to make a guess at the future of Hour of Devastation , I'd say that it will react like Dragons of Tarkir , with some cards increasing in price from presales as people figure out what cards are good for Standard (the fact that fewer people will crack boxes thanks to the low expected value makes this even more likely to happen), but not to the same extreme
The disable/ATK down effects on the original 102 was added to the effects provided by monsters if used for Xyz Summons using 3 or more materials
As far as I know, it won't stop on-Summon effects either, since those activate as soon as the monster is Summoned and this Trap activated in response would only be chained to the effect, but it won't negate it