mIRC doesnt support gifs or anim gifs because the author of the gif technology wont allow it to be used anywhere without applying for a licence (i think - stupid idea) if the author of gif technology reads this board, he might also try looking around the internet at all those gifs being used on hundreds, no wait thousands errrr, millions of websites, theres tons of gifs and stuff, maybe the gif author might be genourous to allow mIRC to be able to finally have gif support.
To basically answer you... no. They won't they want to make money and they only care about making money. They see those "millions of websites" as "millions of dollars" they couldn't care less if people like gif or if gif is great (which it isn't) they want to make money. What mIRC really should do is add full png and mng. png is a great format supporting all that gif does and more. Ok png doesn't support animations, but thats where mng comes in. It is just like png except it supports animations.
Just to basically sum this up in an analogy, asking Unisys to let you use gif for free is like asking Microsoft to give you a free copy of Windows.... it's not gonna happen.