I am strongly against this.
My reasoning is as follows: The free 1-month subscription any Amazon Prime subscriber is given every month of their Amazon Prime subscription is an expense only proposition. It is a marketing tool that is meant to drive engagement on Twitch. If viewers who are Amazon Prime subscribers are reminded to give their Prime Sub to the streamer they had previously given it to, the only one who benefits from this is that streamer who receive the last Prime Sub. There will be no even distribution and the viewer is not encouraged to seek out new streamers to watch and give that "free" Prime Sub to, with the featured broadcasters on the front page or who already make the most in ad revenue due to their high viewer counts reaping the lions share of it. This already happens with the current system, but viewers being notified to renew it without the broadcaster making content that drags them in all by itself would just amplify the issue of driving engagement and revenue to those who are already receiving quite a lot of it, and no longer drive any genuine engagement to the rest of Twitch and its discovery channels. And worse, it is suggestive to the viewer in a manner that is very little to their benefit.
I would posit that turning the purple "Subscribe" button into a "Prime Sub available" button on every channel that has less than 350 subscribers (Prime subs do not and also should not contribute to the Partner+ requirement) until used is a much better option. This way at least, the smaller streamers viewers can actually still talk to and interact with in a responsive manner could get a much needed revenue boost that keeps them doing what they are doing instead of giving up on their dreams of being a streamer.

I agree with Lisandro MRT, no sub should be forced

Making my yearly visit to this "Planned" feature.
See you again in 2023 old friend.

Really disappointing to still see this marked as planned

this has been marked as planned for 5 years

It's 2022 and it's still marked as planned...I'd personally like to see this happen, as I like to give my Prime sub to the same person every month.

Well then. I notice this was flagged as "PLANNED · Aug 1, 2017" and yet I still have to manually resub to a channel with my prime...

sorry i dont want to be rude or anything, but whey it re subs to a streamer i never saw or folow.. shouldnt force to random sub to any twich that u arent folowing at least doesnt make sense.. i was gonna sub to ydcb or tyler or masta and this did go sub some one i never wear or isnt my type of streamer at all its a litle anoying!

Today twitch added a feature to notify you when your paid subscriptions expire, prime subs should be added to this already existing feature because they do not automatically renew.

I like both of the ideas you guys have come up with!

An alternative feature to this would be the ability to toggle automatic resubscription, which would allow us to gain certain perks that Channels have set for 1,2,3,4,etc year subscribers

This would be a nifty feature.