The type of aircraft a gate is capable of handling is coded in the actual airport file, and you will see that when you select a gate for your departure.
They must say Heavy in order to have a widebody there.
Of the thirty some gates in “E”, only six have the “heavy” designation, (E19, 20, 27, 34, 42, &67) the rest are “medium”.
Your chances therefore are slim, but if your timing is right, you might be able to spot a widebody at those gates.
There is no current way to easily change the gate assignments.
However, a new product for MSFS, called the Scenery Gateway System has just recently entered a limited beta testing process.
This system will allow MSFS users to edit and correct these types of airport issues.
There is no estimated date yet as to when this will be released.