You need to maintain and clean the public areas sufficient to retain satisfaction of your upper class vacationers. If you don't, it may begin a downward spiral such that you can't attract upper class vacationers and then the concierge services may stop making sense, you may have to cut rents to fill the units and pretty soon it's basically a slum.
If you design it per my instructions to have adequate ventilation, a trash chute etc, it should be fine IF you actually maintain it. Keep it clean, do touch up painting and such as needed and maintain pipes and other mechanical systems.
Air conditioning units, hot water heaters aand old pipes are known sources of Legionella. Although it is best known as a cause of deadly Legionnaire's, it also causes a lesser known chronic (not so deadly) condition called Pontiac.
Sick tentants who have trouble working full time will have trouble paying their rent and this is potentially another cause of a downward spiral into these units being slum housing.
The only design detail I can think of to suggest is if you are in very rainy areas with higher than average Legionella risk, consider going with hot water on demand systems instead of standard boilers. Boilers are a known vector for Legionella.
If you follow the instructions for adequate ventilation and passive solar design that doesn't require air conditioning to stay adequately cool in summer, that should help protect against both Legionella and mold. Both are underdiagnosed causes of serious health issues and my firsthand experience with living in poverty housing suggests that both help make such housing a slum full of cranky, underemployed people and help keep it a slum.
The intent of this project is to provide a middle class lifestyle on a modest budget where you can eat well, stay healthy and sort your problems such that a short-term stint of budget issues doesn't become an inescapable poverty trap for individual residents.
If your permanent local residents using this as a primary residence can maintain their health and a middle class lifestyle, upper class vacationers won't mind mixing and mingling with locals and may decide to use this as their retirement home at some point. If locals using it as their primary residence basically turn into drug addicts and people you would basically expect to meet at a homeless services center, upper class vacationers will gradually be driven away.
Upper class vacationers will not care if, say, local seniors on a fixed income, single moms and college students with not much money live next door. They will care very much if most residents have that "criminal scum from the slum" vibe.
If the locals have functioning lives, they will likely consider it to be a feature, not a bug, that they get to mix and mingle with locals casually in the public spaces if they so choose. It has the potential to give them insider information compared to vacationers at hotels and, again, may incline them to eventually retire there, either in one of these units or in a larger home elsewhere in town.