I personally think the question is deeper than a name. The smartphone market is saturated with Android taking over 80-percent and iPhone taking pretty much the rest. A **smartphone** from Microsoft with *any* name would still have to contend *as* a smartphone where there would be little chance of success.
I believe a new category of device, running Windows 10, Andromeda, with CSHell on a pocketable PC with Continuum, that can be full PC when docked, phablet-sized handheld perhaps when folded and a tablet when unfolded differentiates the device on a more fundamental basis than what the name would accomplish alone.
With telephony it could still do what a phone does, but would be categoriacally a new type of pocket PC. With that positioning I would suggest the Surface branding so that it falls in line with the Surface family of devices under the Studio, Pro, Laptop and Hub as an ultramobile PC with a strong inking, digital notepad focus.
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This is how Microsoft could position ultramobike PCs.
Microsoft needs to leverage partnerships, eSIM and edge computing to position ultramobile PCs:
https://www.windowscentral.com/surf...omputing-could-help-position-ultra-mobile-pcs