Here's the source for Meaghan's tweet, confirming Equestria Girls as canon.
Does it need to be sourced for every page of the thread? It was on page four. o_O
Meaghan's tweet and his appearance in a recent episode confirms his place as a canon character. Maybe you didn't like him. Maybe you hated Equestria Girls. Opinions on an MLP forum don't change that Flash is considered part of the MLP universe and has made an appearance in the show now.
My only points have been that Flash is canon and that romance has not only been explored in MLP (Hearts and Hooves Day anyone?) but that Twilight being in a romantic relationship does not take her strong character and automatically make her weak. Unless the relationship ends poorly, there is no need for it to destroy her friendships with the other Mane Six.
And of course Flash needs development. And I'd welcome Lyra development too. Or heck even Pinkie's family. I like character development. For any character. Is that a bad thing?
As for marketing, the entire show is marketing for the toys. If you want to break it down, all of their pets are marketing, the Crystal Empire, Cadence and Shining Armor, the royal wedding, and all of season four are also all marketing tools to sell toys. That's the entire show. The entire show is a marketing tool to sell toys. That's what it always has been. That's what Hasbro does, from MLP to Transformers and GI Joe to the newly acquired Strawberry Shortcake and Littlest Pet Shop toylines. It's all marketing and it's all meant to sell a product. That's how Hasbro operates and how it has always operated.
Also, who is mad? o_O