Isn't the point that you interpret the canons in the right spirit? There have been disputes about all sorts of issues: the Trinity, the nature(s) of Christ, the Theotokos, icons, calendars etc etc. Even if a canon referring to heretics would have referred to a particular kind of heresy at the time it was promulgated, is it really reasonable, or in the spirit of the canon, to argue that it must only then be applied with reference to that specific heresy, that other heresies don't "count"?
No, it isn't. Because simply the term had another meaning, whether that gets into your brain or not. Do you think St. Basil did not know any of those we would call Christian heretics today? He did know them, but in his terminology, they were only schismatics.
I would also note that words - and concepts - have meaning. Orthodox Christians and Roman Catholics alike have referred to the events following 1054 and continuing through the present as - "The Great Schism". One would think there is a reason for that in an historical context.
But, as Wikipedia notes: " In Western Christianity, "heresy" most commonly refers to those beliefs which were declared to be anathema by any of the ecumenical councils recognized by the Catholic Church. In the East, the term "heresy" is eclectic and can refer to anything at variance with Church tradition
. " http://en.wikipedia.org/wiki/Heresy_in_Christianity
That, in bold, is the understatement of all time. Orthodoxwiki dances around the issue rather effortlessly in an article which requires "clean up." http://orthodoxwiki.org/Heresy
It would seem that from an Orthodox pov, there are heretics and there are Heretics and finally there ARE HERETICS. Some it would seem are just misguided schismatics and others are on the cusp of apostasy. And a (h)eretic to one Orthodox observer is a fire breathing HERETIC to another.
Roman Catholics have a tough time grasping this "elasticity" in meaning. We Orthodox may use the same term while meaning very different things.