I don't see the need to make this xenophobic list a sticky on UU. It excludes far too many ukulele makers to be seen as useful for a serious ukulele collector or player. The author only joined UU in September 2017, a major failing of the list is the exclusion of a lot of UU members who have been members for many years before September 2017 and who have contributed a lot UU and who make excellent musical instruments. It also excludes some great makers who work in Europe, Asia, and Australasia.
While some of the long term members who have been excluded by silly rules may be offended by the exclusion, I don't have a problem with the thread, it is something many collectors do. Make a list of nearby makers, and find one to order your new uke from. A good take away for all UU members is to have a go at identifying all your local makers, where ever you live. Many will only be found by word of mouth and wont really want to see their name in lights on a board like UU, they will have plenty of work and wont need a newbie annoying them with questions unless there is a serious intent to buy.
However, the step of providing free advertising to such a confined exclusive group as a sticky on UU is really something that does not do a lot for the international membership of UU when they are looking for a maker. A maker sticky on UU needs to have much wider rules so that all members, can see a wide range of options when they are looking for a custom uke. It is not hard for UU members to narrow down the list themselves, most really don't need to be told how to look at a list of makers and work out which ones work in the USA.
And for the makers who are UU members, if you feel left out, do something (positive) about it. If other UU members don't seem to realise that you exist when they are buying a new ukulele, UU has some rules which help out and allow some commercial activities to help you become better known if you want to be. You can't expect to hide in the luthiers lounge and connect with potential buyers if you want to sell product. Of course many UU member makers are not into hyped up sales and marketing plans, they just join to get some knowledge and encouragement, which is fine, they probably would not want to be on a list like the one in the OP. However, if you do want to be on such a list, whether it is posted or just made at home by a potential customer, you really do need to have a sales and marketing plan which targets the market that is following the OP. You wont sell anything by hoping someone is going to find you by ESP. Selling is not easy, it requires active work and planning, if you want to sell you need to do the work and planning.