I'd offhand say no. He is referring to the subject of "mIRC" not irc programs in general. That being said, "the" would be appropriate, and does not insinuate that its "the only irc client"
consider it as "the IRC client mIRC" and did you neglect to note the rest of the answer where he explains client vs server and states there are many of each?
yep, was interesting to see how people would reply in these "circumstances" so to speak :P i wasnt meaning it half seriously and yes ofc i read the rest of the answer