The Maks do have chrome-lined barrels. I have never heard of anyone ever having an issue with Hoppes in a Mak barrel. I use it almost exclusively. I believe that what you are thinking of is the reaction between Hoppes and nickel, not chrome.
What I read was that chrome doesn't adhere well, or not at all, to steel. Therefore, manufacturers first line the barrel with copper. Then they apply the chrome. (Copper does bind well to steel and chrome does bond well to copper.) The problem exists, as I understand it, because Hoppes is designed to remove copper from barrels. So, if there are any cracks, holes, etc in the chrome, the Hoppes can get behind the chrome and attack the copper.
I just got my first Mak and have cleaned it once with Hoppes. After reading this tidbit, however, I'm going to use Breakfree on my barrel from now on.
From my experience Hoppes #9 doesn't clean copper from a barrel with a darn. That is why shooters (like me) who use it to remove carbon fouling must use a second copper solvent to remove copper fouling from their rifle and pistol barrels.
Its a different story if you happen to be using Hoppe's Copper Solvent, which is designed to remove copper fouling in addition to carbon fouling - then it may be a problem.
If you are still in a panic about using Hoppes to clean your Mak, then don't use it. However, there is absolutely no evidence that Hoppes has any adverse effect on the chrome-lined barrels of the Maks.