Frank has now given Eric Jacobson his blessing to do live appearances as Miss Piggy and Fozzie, but this doesn't mean he has completely relinquished his classic characters. His Muppet appearances are still based on availability. Even if he weren't able to puppeteer, if he were available to loop a voice, he would do so. I think the day is still a long way off when Frank announces his retirement.
As for Sesame Street. As I've said elsewhere, Frank recorded two days for season 34 (mostly Ernie and Bert), and one day for season 33 (Letter of the Day segments). This is quite a lot given Sesame's reduced taping schedule.
secret squirrel