The rumor is that all the masters to the nutthowze shit was destroyed just to fuck tech
IcyRoc's the one who said he threw them all in his fireplace. However, since that statement, he 'leaked' I Can Get Grim on his MySpace, so...
Anghellic wasn't even released by Strange anyway.
It was released through a Joint Venture with JCOR, so Strange did have a part in the release.
However, to the original poster, the two major reasons have already been stated. The fact Calm & The Worst wasn't released by Strange surely plays a part, though I think it has a lot to do with the fact Anghellic was his first national release, everything prior was just local. It's like, if you're an artist to be taken seriously, I you going to consider your first real album your debut, or that 4 track EP you sold out of your truck to only a couple thousand fans. (Not saying his earlier releases only sold a couple thousand or anything though)
However, it's not like Tech never mentions The Calm, however he rarely ever makes a mention of The Worst, is he even aware of the release of The Worst and/or The Worst 2K Edition? Look at his comments about 'Strange' on Vintage Tech. Ha.