Yes, maintenance fees generally increase each year and must reflect only the costs to operate the resort. They can't increase more than 15% a year per the POS. The limit does not apply to the property tax portion of the dues. AFAIK, there is no limit to property tax increases, We have never seen an increase anywhere near 15% in one year for any of the DVC resorts (including the taxes).
FWIW, I don't think an average increase between 2-3% each year (including the taxes) is unreasonable. The
maintenance cost plus taxes for our home in Minnesota goes up more than that every year and I can't believe that the maintenance costs plus taxes for the people who live in New York go up less than 2-3% per year, either.