YES, it makes a big difference.
Using the Main Entrance Plaza turnstiles is the better option, since you can start earlier, go through the security check next to Sephora and then get in line at the DCA turnstiles (Make sure they are marked "Extra Magic Hour") Disney can open as many as needed based on the crowd size, and everyone gets in at opening.
Due to the retrofitting of the GCH DCA entrance next to Napa Rose, they can't even start the Security check process until park opening, and limited to two turnstiles. So to get in the park at opening,you need to be first in line, and that requires bring in line maybe 20 to 30 minutes oprio to the EMH starting time. Then you could end up with a group with strolers and a lot of things for security to check, so youcould spend the first half hour just trying to get into the park.
Going straight to
Disneyland Park,that is go through the Security Check at Sephora and get in line.
If you use the DCA GCH entrance, first off, it might not be open when Disneyland opens, and if they do open at the same time, you need to get into DCA, walk through the park to the Main Entrance Plaza, and then walk to the Disneyland Turnstiles, have your ticket media scanned again. Once again a time eater.
Now, once the morning rush is over, it really doesn't matter which entrance you use.