Universal was built with the regular lines accessible to wheelchairs/
ecvs and you may find that Universal is very accessible if that is what you need, especially if you can get out of the wheelchair/
ecv to board the rides that are not totally wheelchair accessible. If the regular lines are accessible and accessibility is all that is needed, then it's perfectly acceptable/expected to be told to use the regular line.
(The lines in the older WDW parks were not accessible to start with, but the newer parks and new/renovated rides at the older parks are usually fully accessible).
For mosts guests with wheelchairs or ecvs, an accessible line is all they need. Some people have additional needs besides just being able to roll in (like a quieter place to wait, avoid the sun, etc) because they have conditions that involve more than just mobility.
In past threads about Universal, most people with wheelchairs or ecvs who posted did not have the same experience with Universal that you did (ie ushered to the front of lines without asking), but they didn't expect front of the line access. Many who needed and requested additional accomidations besides an accessible line reported being told that the queues were wheelchair accessible and that was all that was necessary to provide. Most people with wheelchairs or ecvs don't expect front of the line access and would not complain about Universal not giving it to them, but some guests need other things besides just access.
From a positive standpoint, Universal has a very good
Rider's Assistance Guide that can be downloaded from their website. It lists exactly what capabilities are needed to go on all of their attractions.
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