In particular, X-Force #56, which was published in 1996, has the following paragraph:
She has lost Warpath. [Shatterstar] has lost Rictor. Both see these missing teammates as "friends." Both too stubborn to admit they may mean more then that.
If Liefeld claims that Shatterstar's coming out is "contrived", it means he hasn't been paying attentio to the character for at least 13 years.