1: the numbers of specialists will stay the same. the "quality" of the applicants will decrease, but specialty programs will definitely still fill their positions.
2: The decision to specialize will be less appealing to those who have to take on debt, which is the majority of applicants. The average applicant will initially be those from wealthier familes, so over the next few years those who come from wealthy families will be the majority of applicants.
3: Eventually, as time goes on the average applicant will be a regular dentist who has had time to save longer. It will deter young dentists from buying practices as they will know they eventually want to specialize but need to save up first to pay their school debt. So more dentists in their early career will be available to work for corporations. salaries at corporations will go down as it becomes more competitive.
4: people will still want to specialize to escape general dentistry
tldr: next few years only rich people will specialize, as time goes on numbers will go back to normal but applicants will just be older