Party Gift Pool
This suggestion is to create a Gift Pool function. The streamer sets a date in the future for the "party" and people can submit gifted subs to the party for a slight discount. As an example, a streamer sets a party date two weeks out. The channel followers can donate gifted subs for two weeks. During the party stream, when the streamer hits the button, the gifted subs are pushed out, giving a preference to those in the chat first, maybe even adding to their current subscription.
This would allow streamers to host a party event that encourages everyone to attend in order to receive a reward, but also gives people something to donate towards as a community.
This could be restricted to a minimum number of gifted subs and to once a month to prevent abuse. If Twitch allows people to purchase emotes or other things to throw into the pool, or donate drops to the pool, it would allow for communities to celebrate in fashion.