Be careful.

Theoretically speaking, you cannot benefit from Automatic Visa Revalidation because you have changed your status. meaning you need to get new visa stamp from US consulate. However, I know cases like you and came back without new visa stamp. It's the decision of the IO at the border, who can let you in or not. If you decide to go without getting new visa stamp, you'd better get your I20 endorsed and make sure it is VALID. So is your I94. And also check if your name is on SEVIS to be on the safe side.