If I can give you a strong hint: grandfather in everybody at todays rates and prices and simply drop the bronze plan from your new signup page. That way you keep your existing users happy. The last thing you want is to kill off your early adopters. Besides the very bad PR. I'm a huge gitlab advocate and this move sits wrong with me. Your 'bronze' users did not ask you to develop features that they probably won't use anyway so your justification to force them to pay more sounds hollow at best and disingenuous at worst. Fix it while you still can.
I'm struggling to see why you need further research 9 months down the road on such an obvious issue.
Just to put it in perspective, your lowest non-free tier is 50% more expensive than the standard Office365 Business subscription... for which non-dev does this make any kind of sense?
The fact that you then proceed to launch the new prices regardless of having a solution for this obvious issue is to me a really strong indicator that GitLab is not the way to go once we're moving away from the self-hosted JIRA later this year.
We're an organisation that builds and runs products (mostly in the open but with occasional confidential issues). We are a silver member with about a dozen developers but 3x as non-developers who need to participate on issues.
Although most issues are open, there are occasionally confidential issues that staff need to be able to view and comment on. The entire annual seat license is required for every member, to work on only a handful of tickets. It's very poor value for money.
For the devs the license is reasonable value for money (we use CI, git, docker repos etc).
But for the majority of staff, and therefore the whole org, value for money is very bad. The GitLab pricing model gives us no option.
It's made it a more difficult sell in the organisation. Boasting about dev features leaves a bad taste in the mouth when only the minority of seat licenses actually need to use them.