Not necessary but a good idea. Inspect the valve stem where it enters the tube. If there is a lot of corrosion there I'd replace it. Just so you know, HD tubes are not necessary unless you do a lot of single track and on this bike that is a tall order.
I just took off the stocker tires with only 900 miles for something more agressive. And remembering quite a while back someone saying the stock tubes and rim(spoke) strips were garbage, I did not find that to be the case.
I pulled my stock tires off around 4000 miles and re-used the tubes/rim strips. Did not give it a 2nd thought, they looked fine.
Almost kept mine on a 3rd season in 3rd set of tires but recently installed mousses. Stems had slight rust I scraped off and sprayed with Boeshield and reinstalled. Unlike mtb... More solid and reinforced so not much of an issue. All rubber looked good as I coat well with powder. Many will patch and patch again. Only real issue is rubber/butyl decomposing in say 5 yrs time. Even new tubes in boxes might develop cracks just folded in boxes. Just tossed 8 inner tubes I had since 2007 for mountain bike but they were light tubes. All plastic/rubber is timed to self destruct at various times.
I'm on my 4th set of tyres / 17000km / 2 years with the original tubes. I haven't looked at the tubes myself, because I don't do the tyre changes, but the bloke who does at the local bike shop would suggest that I buy new tubes if he thought that they might fail so I guess he mustn't see any issues. The bike does get ridden regularly, not every day, but it wouldn't often go more than 2 weeks without at least getting a short ride. Tyres and tubes will stay "fresher" when they are regularly stressed, and will deteriorate more quickly when they are left still.
New tires = new tubes. No question in my mind. Few extra dollars vs. my safety? I keep a spare set of tubes in my bags, when I change tires I take those tubes for my spares, throwing out the old set.
Can't see any reason for new tubes at every tire change. If they've been fitted correctly in the first place (no folds/ no pinch-marks etc) and there aren't any wear/ chafing marks on them I've been happily using them over and over on all sorts of bikes over the last 40 years. No problems at all. It it ain't broke, don't fix it.
I coat my tubes with rubber grease rather than powder, the tube is less lightly to get "pinched" a trick learned from some for the fastest & aggressive enduro & desert racers I use self-amalgamating tape as rim tape I carry my old tubes in plastic zip-lock bags as spare
I put HD tube in mine when I swapped out the OEM tires. I got a flat on the front the first friggen day!!! A tiny thorn was all it took in the thin stock tubes. After I put in HD tubes I don't change them every time, I just inspect them (no rust on the stem etc.) and if they look good, back in they go.
