Footnote 9 of the decision, citations omitted, highlights mine:
To be clear, nothing in our analysis should be interpreted to suggest the unconstitutionality of the 43 States’ “shall-issue” licensing regimes, under which “a general desire for self-defense is sufficient to obtain a [permit].” Because these licensing regimes do not require applicants to show an atypical need for armed self-defense, they do not necessarily prevent “law-abiding, responsible citizens” from exercising their Second Amendment right to public carry. Rather, it appears that these shall-issue regimes, which often require applicants to undergo a background check or pass a firearms safety course, are designed to ensure only that those bearing arms in the jurisdiction are, in fact, “law-abiding, responsible citizens". And they likewise appear to contain only “narrow, objective, and definite standards” guiding licensing officials, rather than requiring the “appraisal of facts, the exercise of judgment, and the formation of an opinion" -- features that typify proper-cause standards like New York’s. That said, because any permitting scheme can be put toward abusive ends, we do not rule out constitutional challenges to shall-issue regimes where, for example, lengthy wait times in processing license applications or exorbitant fees deny ordinary citizens their right to public carry.
Thomas must have been writing this for years, considering the number of conditions he considered. Now, getting the lower courts to actually apply the ruling may be a bigger issue.