I mean, maybe? Usually though, just changing the tire, if they didn't do an adjustment, would be just as tight as it was before I think. The final belt drive is tightened my moving the wheel back, which involves loosening the axle, tigthening adjuster bolts evenly on both sides, etc. If they didn't touch the adjuster bolts, then it should be the same tightness it was before. I never loosened the belt to pull the axle, I always just stuck a wrench on it and twisted while pushing it from the other side. Then wheel goes back on exactly same place it was before.
But, I haven't worked on Sportsters, so I dunno how much different those would be. I also have no idea what the symptoms would be of a belt that was too tight.
Quick and dirty belt test is go out there midway on the top strand and see if you can turn the belt 90°. That's not the proper way to check it, but it's likely too tight if you can't... at least on a big twin. Really you're supposed to measure the deflection with 10 lbs of force or something like that. They even make a tool for it.
And the chain, man I never could adjust them right through the chain inspection, trying to lift the tensioner and measure slack, I just take the whole primary cover off. Yeah, cover gasket (for mine anyway) is like $20-30, not the cheapest way to do it but I can know it's right. Plus, I keep my chain at the tighter end, roll the thing over until I find the tightest spot (cold) then tighten it to the tightest side of the spec range, but I have less clearance because of my setup.
Usually if it's light chain slap, that goes away when you rev up or start moving, not get worse.