You would think so, but with all the acid it doesn’t end up very sweet, more of a sweet and sour taste similar to what you get with KC style BBQ sauce, but with more of a…sour/umami thing going on than your normal BBQ. And you have to understand you are making a large quantity of the stuff so it’s all about proportions. I make enough to mix into the meatloaf, cover the top and both sides and have extra left over. You can probably cut the whole recipe in half if you are only going to glaze the top.
Never had ketchup on it, it was always tomato soup when I was growing up. And I have to agree with a cousin of mine, who at the age of 4 or 5, when asked if she wanted more meatloaf, announced:
“Yes, but don’t put any of that friggin soup on it!” 
Neither of the above. When I was growing up, my mother put nothing on it.
Nowadays I use teriyaki sauce on meatloaf, or Rochester-style Hot sauce (like “Boss” sauce)
Usually I put A1 in the mix, I don’t put it on top.
My basic recipe is ground chuck, bread crumbs, milk, an egg or two, A1, and either seasoned salt or MSG. Sometimes I sneak a little mustard powder in there, too. I cook diced onion and bell pepper and celery, and add that to the mix.
If we have mashed potatoes, then I make brown gravy. Otherwise, my husband is likely to put catsup on his slices, while I eat mine nekkid. If I get really crazy, I might put a little pizza sauce or BBQ sauce on the meatloaf during the last 10 or 15 minutes of cooking, after I’ve drained it.