Hi Daryl! I see you've done a lot of great work on your Davis family! Welcome to the G2G side of WikiTree!
I think you are asking about this James Davis and his male direct line descendants. I see from this tool that there are possible living descendants who could be tested.
I can clearly tell that none of the patrilineal descendants have recorded their Y-DNA test on WikiTree. Within 24 hours of them doing so, it would show on your profile as well as on every other profile that could be expected to be a possible Y-DNA match.
So either they haven't tested, or they have tested but not recorded it here at WikiTree. (I have a progenitor-type ancestor whose Y-DNA has been discovered, apparently, but those cousins of mine are not yet WikiTree members so it doesn't show up here at WikiTree.)
In case there are non-WT researchers who have got somewhere on this, i would suggest that you check out the Davis project at FTDNA. I think you might have to correspond directly with the group admin. I see that she has mentioned that she is gradually uploading the results that have been shared with the group.
Meanwhile, could you please indicate on your profile that you have done your Y-DNA? This info will be automatically distributed down to all profiles (even private ones that you can't now see) of male-line descendants of your male-line ancestors, and might prompt someone to work with you on this.
Good luck on this quest!
PS - two things that might help when asking questions here on G2G. There are some tag fields at the bottom of the question form. It is really helpful to indicate the profile that you are asking about. I'm assuming that you are asking about https://www.wikitree.com/wiki/Davis-941 because it is a Y-DNA question so i went over to your tree and followed your all-male line until i found someone who seemed to match the description you gave in your question. That is not always going to work for every question, so linking the profile helps us help you.
The other thing that might help you get more and better answers is to use the tag field for keywords related to your question. In your case i would use dna, ydna, davis, pgm (for Puritan Great Migration), massachusetts etc.