Like it or not, that is very common for players to commit to doing a "PG" year after graduation somewhere TBD, and then play with the grade down from their current school grade.
It is definitely happening where we live, and we have two reclassed players on our team, and know of a few that played 2019 last season who will now declare they are declassing and play 2020 next year.
For many parents, it is a more economical way to handle the situation as it only amounts to 1 year of private school tuition down the road vs. moving to private school after 9th grade to repeat 9th grade and then committing to 4 years of private school tuition.
