Occasionally I hear teacher’s say that they question learning from presenters or facilitators who have been out of the classroom for a while. That’s a reasonable concern but it’s also very contextual.
Being a grandparent is much like being a consultant. While it’s been a while since I was “in the trenches” of parenting and also times have changed, my experience and wisdom still has value to today’s parents.

Involved and good grandparents are still aware of the societal challenges of the day. They avoid references to the good old days as some kind of panacea but also try and apply what’s good and has always been good to their grandchildren.
They are keenly aware of their own failures as parents and work to carefully support their children in being better parents than they were.
As a consultant I work to stay relevant. I also acknowledge their are new challenges today that I agree are complex and require support, collaboration and wisdom to solve.
The number of years you’ve been out of the classroom does not have to be a negative. What makes someone a good leader or good teacher has not changed to the degree many think it has. Good pedagogy, building relationships are somewhat universal. Certainly tools and context changes but the foundational principles do not.
I’m a better grandparent than I was a parent. I think I’m probably a better consultant than I was a teacher. My time away from the classroom helped me see many things I did poorly. Part of the challenge of teaching is the lack of time and support avaible to be better. Coaching and consulting is intended to alleviate some of time and support constraints.
The credentials of the consultant should be questioned. But not by how long they’ve been out of the classroom but by the quality of their coaching and facilitation skills and their understanding of current realities.