Hayato watched on TRYING JUST SO HARD to make sense of the situation. Luckily, Souichi was quick to begin explaining. Apparently the whole ordeal was pre-planned. This attack was orchestrated to push the Guardians to rapidly acquiring more strength in order to fight Byakuran. Tsuna was apparently not truly dead in the future, but shot with a bullet that put him in a state that mimicked death. Before that he had made a plan with Souichi and the older Hibari.

Gokudera's eyes widened for a moment. Just Hibari and Souichi? Hibari? Without completely realizing that he was talking aloud he mutters, "W-why didn't he tell me?"

Of course he's not thinking about how bad off he would have been if he had thought the Tenth was dead. Even planned, his calmer more mature older self would still be pretty broken up about everything. Still, it doesn't do anything to stop the little sting of hurt his younger self felt by being left out.

Souichi continues explaining on. The girls and kids (and possibly Ryuutaro) had been brought to give the guardians something to fight for to protect. Tsuna protested what he saw as ruthless cruelty from his older self, only to be shouted at by Souichi. That was how bad their situation was. They had to resort to such horrible and drastic measures because Byakuran was that dangerous.