Not just were ones like Scolipede and Yanmega available, the three 500stat Bugs all got a mega evolution each too.
And its not even that they tried having 5 Dragons, as besides Goodra and Zygarde, they were all secondary, menaing the main point for the pokemons addition was to add a line of their primary type (there would be 0 poison types without Dragalge, Tyrunt was given since they decided to for another pair of fossils, and with Noivern we got the first proper Flying type in history), the Dragon types merely went well along to their concepts.
Also the pool of Dragons that aren't pseudo-legends was really small...now it looks like there is actually diversity.
They cannot do everything in every gen, and Id rather they wouldn't focus on the same stuff every time either. So I am immensely pleased by the additions to each type.
As with Pyroar and Heliolisk, a secondary Normal type is a first, and its a legitimate question as to wtf is going on.
Now, I think I've figured out the reasoning behind their secondary Normal types:
-PyROAR: with all the Normal sound-based moves and having roar in its name, this one seems obvious
-Heliolisk: here we have a case of boosting something as simple as running with converted electricity.
Here is my theory on what this is about, for next time we see a /Normal type:
Such Pokemon use their main type as a source to power up trivial skills, sicne both of those pokemons dex entries seem to imply
"The stronger the opponent it faces, the more heat surges from its mane and the more power flows through its body"
"It stimulates its muscles with electricity, boosting the strength in its legs and enabling it to run 100 yards in five seconds"