LTE band 12 is a very, very common GSM band for both the United States and Canada, and most Nokia Global phones don't have it. As I understand it, band 17 is not necessary if band 12 is available because band 17 is just a partial subset of the full band 12. Including band 12 would greatly increase the number of Nokia phones that would function properly in North America.
I was ready to buy a 64g/4g Nokia 8 Global TA-1004 for use both in the US and for world travel. Then I realized it lacked the essential band 12. In order to have access to band 12, my only Nokia option was to settle for the much less expensive Nokia 6.1 32g/3g US version, which I just ordered. Even the more desirable 64g/4g version of the 6.1 lacks band 12.
A true global phone should at least include the major GSM LTE bands of the world, in my opinion. The Chinese manufacturers, like Oneplus, seem to address this issue very well, perhaps HMD Global could consider this approach also.