At least as described by the OP, I have a hard time believing IBM is doing this. There are a whole bunch of markets -- far more than they listed in their flagship/hub site list -- where a vendor like IBM would have a several - a few dozen dedicated teams that just serve local clients. Now, in a lot of cases (but by no means all) the sales engineers can get badged at their customers and spend a few days a week onsite. While not unheard of, especially at the largest shops, its less common for the account managers to be badged and have unfettered access.

That said, I've never worked at IBM, and the sales segments they listed in the article (strategic, enterprise, etc.) are notoriously company-specific. But, I can't imagine the ones in the exception list cover all of teams with named accounts.

Deliberately placing your sales teams in different cities than their clients is almost always an incredibly dumb idea, WFH or not. In 15 years of sales engineering/sales engineering management, I remember exactly one account team we deliberately placed outside of their client geography, and that was because the client was so spread out, it made more sense to put the team close to a big airport than pick a single client site to place them near.

edit - I’m talking about dedicated/assigned teams, not inside sales or startups that have one or a handful of teams to cover everything.