Motorola just announced the Thinkphone - the Lenovo/Motorola phone interpretation of a Thinkpad computer. This sounds like a phone that in time could be a desirable target for /e/OS.
It will only by available as a B2B product (so, not available to the broader public, but sold to companies). That means in 2-3 years those phones will reach the 2nd hand market.
I am curious to see it out in the wild (and then with /e/OS)
Regain your privacy! Adopt /e/ the unGoogled mobile OS and online services
if it’s targeted at b2b / MDM crowd, hard to know if those will be able to be oem unlocked when they hit aftermarket in a few years
Well, we can hope at least 
But Motorola has been rather one of the easy candidates with their phones.
seen floating the device for 520€ and up to 700€
kernel source for the Motorola Thinkphone (XT2309-2 - codename “bronco”) are linked in this xda thread.
I have no reason to not expect it to be unlockable, Motorola has been effortless in this regard in the past.