A few thoughts...
1) This could make lower tier bowl games more interesting i.e., why not give some young guys reps?
2) Would any teams view this as an opportunity to specialize roles for incoming freshmen e.g., COFH, could you in theory have a freshman sit out all year and get really good at one thing, whether it's a pass rush, punt return, trick play, etc. and save it for the Saturday after Thanksgiving? Potentially very challenging to scout those players, tendencies and line-ups.
3) This rule change makes it easier to avoid play guys who are playing hurt/on the verge of greater injury. A guy like Connor Hansen wouldn't have had his shirt burned last year, but more importantly he might have been inserted in the lineup sooner to relieve starters and our thin OL from having to push through.