While there are variations in the palate of Canadian whisky as exemplified by the available brands, I woould say the typical palate is one that combines:
(i) light flavor, due to the predominance of the high-proof (low congeneric) base used to make Canadian whisky;
(ii) oakiness but not a charred taste, which comes from minimum aging of 3 years in oak barrels (generally, used barrels); and
(iii) a discernible flavor of straight (low proof) whisky (traditionally rye but other grain whisky types are made and added in-house for this purpose including corn and barley-based whiskies).
This has led to charges of "brown vodka" but in fact Canadian is better than that (much of it, anyway). This is because of item no. (iii) above, but the problem is (in my view) most Canadian whiskies don't contain enough of the flavoring whisky so they tend to blandness. Fortunately this is not hard to fix for those who enjoy making cocktails.
Before I get to that, why does Lot 40, a straight (uncut) Canadian rye, not taste like an American straight rye? Because evidently it is not aged in new charrred wood. If it was it would taste close to Wild Turkey rye or Old Overholt rye. This is why Lot 40 tastes quite a bit like the Old Potrero rye whiskey which is aged in toasted casks.
How can we taste a "better", more "authentic" Canadian whisky? Add real rye whisky to it. Canadian Club's 10 year old Special Reserve whisky is a good starting point. It is a good one to use because while not tasting like Lot 40 it has a fairly rich, "rye-friendly" flavor. This surely derives in part at least from its bigger-than-usual component of flavoring whisky (so Corby's told me). But arguably the palate is still too timid. Now, add a dash of Lot 40 to it: the result is quite startling in that a much better drink (to my taste) results. The "orange liqueur" taste of the Lot 40, which on its own arguably (per Chuck) is, "too much of a good thing" comes through clearly in the mixture but is softened and "displayed" by the velvety and complex toasty flavor of the CC. One can use any Canadian whisky as the base and can use an American rye instead of Lot 40 to add more flavor (I think Sazerac 18 year old rye would work well). I have found the CC 10 year old (blue label)/Lot 40 combination about the best to date. This may be because both products are made by Hiram Walker/Allied Domecq. In fact, I believe this CC 10 year old already has some Lot 40 in it or a whisky which is very similar to Lot 40, so adding more just improves the taste, is on the continuum so to speak. I added about a half-ounce to two ounces of CC (1:4). This gave the drink a strong undertone of rye whisky but the drink is very palatable, seemingly offering the best from its components.
When I tasted this mixture I thought, this is how I recall the main brands of Candian whisky tasting 30 years ago. I can't prove that but believe at the time more flavoring whisky was added than is now the case.
P.S. My experiments have convinced me that the reason the flavoring whiskies made in-house in Canada are not sold uncut - Lot 40 was an exception - is, as Chuck speculated earlier, they don't taste all that good. And why is that? Because they aren't aged, or aged exclusively (I believe), in new charred oak. If they were, or if any actually are, they would have to taste quite close to an American straight rye whiskey, or at least one such as Old Overholt which is about 65% rye content. Since new oak aging isn't used in Canada (not invariably for all the components of a Canadian whiskey), the best use that can be made of our "straights" is therefore to add them to high-proof velvety oaky (aged) whiskies - and this is what Hiram Walker did 100 years ago and what Sam Bronfman did later. My experiments have convinced me they did the right thing, and they made a fine whisky style by doing that, appreciated, still, all around the world. But the blends of today at any rate need a bit more real rye in them, that would close the circle that arguably opened when too little of the flavoring whiskies started to be used.
This is just my opinion, having thought about these matters for some time, however.