That wouldn’t be a problem at all. Many businesses already do this (DAS design) either customer specific on their floor/suite, or the building has a full blown building wide system each tenant can jump on.

Wireless in-building can and will replace wired for most companies for general use (with wired connections directly to servers and not employee level computer work).

Really the only issue is user error from employees (initial connections). In-building antennas permeate through everything fairly well except solid walls, but they still can bounce around solid walls pretty well.

Honestly it makes the most sense for skyscrapers like NYC where tenants move and demo floors every few years. Leaving backbone fiber connections only to their Server rooms.

Wireless service will eventually become more widespread to homes, but wired connections aren’t going away. You’re not going to get more consistent or faster than fiber (you know, the literal speed of light).

Wireless will probably become a budget friendly option that works for 99% of people and wired may be more of a premium. Wireless is better than most people give it credit for and there’s already many countries who rely solely on wireless/cellular (and still have low latency for things like competitive gaming).

So they’re not completely wrong, but it’s unlikely it’ll be soon. Especially if you’re in a low population area and already have service.