I didn't review all the listed models, but for the two top-featured machines per model number ...

MVWB755Y description says it includes a supplementary heater, BUT the parts list does NOT show a heating element and there's no mention of water heating in the linked user manual. It uses the same mechanical design (F&P SmartDrive motor) as MVWB850W.

MVWX700X is the updated belt-drive mechanical design, also without water heating.

MVWB850W clearly shows a heating element in the parts list.

Had a technician here for a Whirlpool Freezer problem and he said the Maytag Bravos 850 has been discontinued. Also was just at Lowe's and they didn't have any either.
I've only had this washer & dryer for about three weeks. Who would have thought!!!

The 850 is being replaced with the 950. Should be out soon.

Just did a Google search on: Maytag MVWB950

Here is a link that might be useful: Maytag Bravos XL HE Top Load Washer with PowerWash System

Correction on my earlier post. There will be a 750, 850, and 950. These have been revised and the capacity increased from 4 cubic feet to 4.6 cubic feet. A smidge larger than LG and a smidge smaller than the Samsung.

Whirlpool will offer similar 4.6 cf models. They are WTW8200, WTW8600, and WTW8800. The impeller on the Whirlpool models is wrapped in a soft-touch material that's supposed to be gentler to fabrics.