This change is interesting. The process of creating parameterized blueprints looks a little tedious, but I'm pretty sure that's just inherent to the idea in general and there isn't much room to make it better, and I imagine the ease of using such blueprints that are e.g. downloaded from the internet is perfectly fine.
I play a lot of Factorio in multiplayer, with a group where not everyone has the same desire to make blueprints, and we in-general resist just downloading designs off the internet and try to do everything in-house. This leads to a lot of asymmetric gameplay, where e.g. I may design a blueprint and others will use them. I think this kind of change will work well overall for that (complex train systems are now a reality) but might come with the cost of the blueprint producer spending more time faffing around with the blueprint UI.