I've harped on it for years but the rule could just be that the early signing period is actually early like in August before their senior seasons of high school (similar to basketball players signing their NLI's in November of their senior season) so they could lock themselves in if they wanted to.
The early signing period did get a little better this year with it coming up here on December 4th instead of the week before Christmas like is has been the past. Also helps with FBS teams not feeling the need to poach coaches in the middle of FCS playoff season now that there's no off-campus recruiting allowed anymore between the early signing period and the first week in January.