Is there a wear groove visible , do you have the makers original specifications , .002 thou may not be a lot, but if it results in lower oil delivery to the bearings?
What was their advice re changing, were they saying it was wear on the cams or the journals, I don't know about yours but do the cams run in the alloy cylinder head directly?
At the end of the day if machine shop advises changing them and is warranting/ guaranteeing their work, then unless cams replaced it may invalidate their warranty.
In this case I believe it's a camshaft issue, but like you @varesecrazy I had a machine shop tell me a crank on a 2.5 Sofim engine was scrap even though it was on standard bearings with one big end journal down to the copper, by the time I had got home they left a message saying miraculously they had located another complete crank and new shells for £250, needless to say in that case I declined their offer and they got no further business from my business!
Incidentally in some cases they can obtain even larger oversizes, many years ago I had a Morris Mini 1000 crank reground and give the guy his due he admitted he c*cked up and took the journal beyond +60 thou, he managed to obtain +80 thou shells and took the crank to that, I rebuilt the engine and it was fine.