I recently asked the question "What Happens when I Radiate a Time Stretch with Time Sifter in play?" I had purposefully added Italics to the card names so that they were distinguishable in the text, making the paragraphs easier to read. My question was just edited and the editor removed all of the Italics in the OP. Why would this have been done?
I can't speak for the editor in question, but I would have done the same thing. While I do understand your reasoning about clarity, italics for game terminology is not a convention used by anyone else here for Magic questions, or indeed any other questions on the site. Given that you've already linked the card names to Gatherer, which highlights them nicely as hyperlinks, and the pre-existence of a style convention, the italics are not really necessary.
I reviewed the edit, and in my opinion, the original use of italics was jarring and odd.
Bear in mind that as the original author, you always have the right to revert changes you don't agree with. But if your intention is clarity for readers, then I suggest you keep the changes, since as far as I'm concerned, the question was improved by the edit.
The main reason I edited your post was to correct the name of the card Timesifter. It's one word, not two. But as long as I was editing, I decided to remove the italics because, as ire_and_curses said, it's conventional among all MTG sites I've seen to write card names in the same font as the surrounding text. The only thing that distinguishes them as card names is the capitalization and optionally a link to Gatherer or a similar site. (And of course the grammatical context.)