I wanted to say, I only found this by asking in a subreddit how to find this page. I had no idea about this page until then, and the original subreddit is private.
I suggest that the mods at least send a message to subscribers on reddit, at least people will know more about the move.
I don't want to speak for others, but one of the reasons I even went to r/startpages was for inspiration. After being inspired, I would comment, participate in conversations, try out things people have made, give feedback and in general be a community member. Without existing content for inspiration, people like me have nothing to do here.
It really frustrates me that I can't go back and look at the existing content. What about all those nice posts about people starting small projects that then become very popular over the years. e.g. nighttab. Reddit Inc's API changes didn't kill this subreddit, the mods did.
IMO, if you want this kbin sub to kick off again, you need to give people access to the existing content. That way when you google "startpage" theres examples to give new-comers to the hobby an idea of what a startpage even is.
Theres a lot of ways to approach this, heres three:
Unprivate the subreddit but make it so nobody can post and pin a post redirecting here. - Easiest and a compromise between continuing your protest and giving people access to the content.
You could even unprivate it long enough for someone to archive all the pages to the internet archive site.
Repost all posts from reddit, to here - would require scraping and mass posting, preferably user a "startpages" bot account.
Make an archive of all the posts.