holiday schedules

I assume you are talking about the Radio City Christmas Spectacular?  If so, that show has four performances on Wednesday, December 6: 11am, 2pm, 5pm, 8pm. 

Show times are not altered or added except for Christmas and New Year's Week.  

Aladdin on Broadway does not have any matinees on Wednesdays in December--only Saturdays and Sundays, and then a few matinees Tuesdays/Thursdays during Christmas week. 

I'm not sure if you mean that your train back to Philadelphia is at 10pm when you say "the train back to philly is 10" but if that is the case, Aladdin does have a 7pm show that night. 

If I were you, I would see the 11am Radio City show and then a 2pm matinee of another Broadway show besides Aladdin and then head back to Philly after that. 

The subway is adjacent to the New Amsterdam on both sides. So if you take the subway back to Penn, you should be ok for a 10pm train. The show should let out by 9:35 or so.

But to directly answer your question : Broadway shows won't likely be adding more shows to their schedule. Actors are contracted to work 8 shows a week. Christmas week sometimes does 9, but usually because either the week before or after only has 7.