People will buy the lowest they think they can get away with then many will find they want to do another event or race but won’t because it hits their limit.
I would maybe consider something like a day pass but zwift have all the numbers so it’s hard to tell without seeing stats. If there are n thousand using 25k free that are now converting to full subscriptions then it’s a win for them which is really the only thing that will matter.
By “lower level” I presume you really mean ‘infrequent’ rather than anything to do with progression level? After all, you could have a higher ‘rank’ user that only uses it in their Winter.
Unfortunately that’s the way most subscriptions work. You pay to have the ability to use it whether you do or don’t. Whilst it could be done by volume, rather than a single ‘all-you-can-eat’ price, whether by distance or time - what happens when that volume runs out? You get booted out of the game or you automatically bump up to the next pricing tier? Probably couldn’t do the latter without some warning and confirmation, which is not the easiest of things to try to implement randomly mid-ride and is hardly what you want popping up mid-race.
Maybe the thought process is to get more people to just do the annual subscription and scrap monthly. Annual rate costs the same as 10 months paid monthly. So If you cancel for 3 months each summer, they’re basically saying don’t bother, just come up with 1 more month’s cost to ride for those 3 months (albeit infrequently – in your case just 6 times) and buy an annual sub.
We have no idea what makes sense for Zwift in terms of pricing tiers or day passes or whatever. They are about to find out whether they convert enough of the freeloaders to paid subs and churn stays manageable enough to justify the change. You and I will not find out, so I’m content to just let them do what they think is best. They’ll know the answer when the high season rolls around. If people want to use some free service during the summer, that doesn’t mean they won’t be back on Zwift in the fall, and that would be an OK outcome if it happens. I’m not aware of any free competitor that is any good so my guess is many of those folks will come back when they are ready to pay.