"... droves..." can be a very subjective term if stated with no actual statistics. Yes, there are nurses leaving the field due to the long hours, verbal and physical threat from patient family members, pressures of working with COVID patients dying daily... needlessly... if they had not paid attention to the anti-vax disinformation. The OP said nothing about these nurses leaving due to the vaccine mandate.
I know of no medical facility that has "reached their goal of nurses". Such a growing field that needs all the personnel they can recruit/train/employ. Probably why the granddaughter works 40+ hours at a nursing home, two half days at a chiropractor's office, while trying to keep up with her coursework towards her RN certification. That's why it is almost criminal a small segment of the population is so enamored with those spreading hate and disinformation they influence even our health care workers to stay home rather than use their training to save lives.