Ed, just to set the record straight I've been in the RE game for 45 years as a general contractor, manufactured home contractor, manufactured home dealer and RE agent/broker, developer, property manager and investor. I too am a current landlord and have always provided the best of conditions for any/all my tenants.
FYI, I did read this question over a few times and to me it looks like this landlord has deceived, if not outright defrauded them. The notion that all the tenants should just up and move is rather cavalier if not outright ridiculous. I know that being the sophisticated RE property manager/landlord that you are you are not naive enough to really think that it would be as simple as that for 25 tenants to pull up stakes and do a "We'll Show You"
You and I being landlords/property managers know that it's not difficult today to attract new tenants. At least not in my neck of the woods. Add to that that once a tenant moves out you can usually re rent at a higher rate. It's a win win for the landlord and a lose lose for the tenant.
Tenants have rights. What this landlord has done to 25 tenants is outright theft and they need a good lesson taught to them. One tenant filing a civil action in small claims court is a waste of time and effort as far as I'm concerned. But power is in numbers.
I'm not suggesting that they file a class action for this one isolated incident. It sounds like this landlord is a bully and an abuser and has no doubt pulled other devious pranks on their tenants for sometime. That's where a good aggressive class action specialist would and could become interested.
The first thing the attorney/s would do is distribute a questionnaire to the tenants asking for a list of their grievances, complaints, concerns, incidents, etc. If after evaluating these questionnaires they felt they had a case they would proceed with an action on a 100% contingency basis. There would be no money coming out of the tenants pockets whatsoever and if there was I'd quickly seek alternative counsel.
As for your comment, "Suing an owner in a class action will cost us all in higher premiums because a stinking lawyer gins up a bunch of angst from some disgruntled tenants... How much do you think this tenant is entitled to, based upon the information you've seen here...? That's laughable and deplorable all in one. It sounds like you have more sympathy and empathy for the bully landlords than you do for the abused tenants.
As to this statement, "By the way... I'm not aware that a pool is a required habitability issue... The question posed was regards the on-site situation and the fact the pool was going to be filled... ". Well then why on Earth did she extort money out of them for the pool,,,,,,,,,,,,,,,,,,, "Instead of fixing the pool, she now told us she's going to fill the pool with sand and turn the area into a BBQ pit, and none of us want that" No doubt in part with the money she stole from the tenants.
I have a very short fuse when it comes to landlord abuse issues. I've seen too many folks being intimidated, harassed and even accosted by idiots like that. They need to be called to the carpet and sometimes you must confront the issue in force.