Dangerous game climate matters. I believe the reason a lot of alaskans prefer controlled round feed isnt for feeding at all, it's for mechanical ejection. Plunger ejectors often fail in the most extreme cold they get up there (sometimes colder than -40 degrees) and I know of one guide that doesn't use any oil or lube on his stainless 77 because he found that if he so much as slightly oils his firing pin mechanics, the firing pin will fail to have full strength on the coldest days of the year. He sprays his gun down with brake clean and leaves it like that, saying that the extra wear on the gun is worth it for his safety.
In Africa, cold weather is not a concern. Dangerous animals charging are a bigger concern there, especially to PH's who have a lot more encounters in their life than the client will. So CRF and double rifles are more often used for their reliability to stop a charge than in AK.
I've never hunted in temps so low that plunger ejectors outright don't work, but I do testing on ammo at -20F whenever the polar vortex gets down that low to make sure that my powder behaves predictably in extreme weather, and I have noticed that ejection is weaker than in the summer. Not by much, but noticeably.
Weatherby uses push feed, plunger ejection. They're nice rifles and I own several, but they wouldn't be my first choice if I had other options for alaska, even without being in bear territory. Just for the reliability of ejection should I need followup shots if hunting in sub 0 temps.