"Howdy, XO," he drawled. The old west affectation common to everyone from the Mariner Valley annoyed Holden. There hadn't been a cowboy on Earth in a hundred years, and Mars didn't have a blade of grass that wasn't under a dome, or a horse that wasn't in a zoo. Mariner Valley had been settled by East Indians, Chinese, and a small contingent of Texans. Apparently, the drawl was viral. They all had it now. "How's the old warhorse today?"
Yep, intentionally modifying your speech patterns to be understood better isn't exactly adopting a new accent, it's just using simpler/common words and enunciating.
In the article they talk about extremely subtle pronounciation changes. It doesn't seem like it was a conscious decision.
I used to have a job where I was the only non-Indian on my team and I didn't go as far as to develop an accent (also I went home every day lol unlike these guys) but I felt like I was unintentionally picking up some Indian affectations/word orders.
Fascinating, as I had no idea it could start to happen this quickly. This really helps explain how regional dialects like the Carolina Brogue emerged in isolated parts of the country/world.
Tangent story, I was in Manitowoc, WI, on a motorcycle trip. In WWII, they built submarines there, and they have a US submarine at a museum on the lake.
You might remember Manitowoc as being the area where Making A Murderer happened. Turns out that series only gives a light impression of the local accent there. The tour guide for that submarine sounded like he was speaking a completely different language from English.