When the price of a Vip Server is changed, all subscriptions are cancelled.
Does this mean all current Vip Servers are cancelled immediately and the player would have to re-buy the subscription again to get in, before their month bought from the previous month is up? (effectively does changing the Vip Server price remove everybody from the Vip Server starting from scratch or not)
My guess is that the VIP server will have auto-renewal cancel, give a refund, and then terminate access until repaid, since this type of behavior can happen with a VIP server having auto-renewal being canceled and running out after 30 days. It would also cause less confusion to stop access compared to just deleting the VIP server.
Keep in mind that I haven’t experience this or attempted it on anyone.
Whilst this isn’t the most of helpful responses, in order to experiment to find out the behaviour you could create an alt account with a VIP server on it, which you then proceed to buy using your main before changing the subscription cost. I’d do this but I think the minimum cost for a VIP server is around 5 - 25 robux and I have less than half of the former.
Though I’d only advise that if you can’t obtain a concrete answer from anyone else.
The answer: The players can still play until the end of their current monthly subscription would have ended.
The wording by Roblox may be confusing to players