I'll be honest: I lack knowledge on a ton of projects made, but I know I can say for sure that dragons looking similar to ponies in a horse franchise isn't new to me. With MYM, it feels like they did that not only to save time and sweat rendering characters, but also to make characters of another species look familiar to kids or other viewers who saw ponies first and dragons later (noting that the said viewers might not know other MLP generations). One style of eyes etc. makes it not look 'out of place', if I can try to guess what the creators thought. Personally, I think it's quite cute!~

Also can't wait for the premiere of Chapter 6 and may everyone have fun!