Well my opinion is this. if its not leaking badly, watch your oil usage, and keep adding as needed.
When the time does come, maybe 50k down the road that it starts leaking more than you would like, well at 100k you should do the timing chain, while in there, you could just have them renew the gasket. there is a new m104 headgasket compared to the older design, with metal inserts to stop them from going bad. I believe this is what I have read on here.
Mine is lightly damp, not even wet or losing oil, there is just a small slightly damp spot near the timing cover and head, other than that I have no problems with mine yet that warrant replacement.
Some will say some oil usage is normal, others wont, I think some oil usage is totally normal, as the engine must burn some of it somewhere slowly if there are no leaks. But in changing my oil, I always get out what I put back in, maybe minus 1/4 to 1/3 of a quart or less, per 3000 miles.
If yours is not leaking badly at all I would just keep an eye on it, I don't think you can do harm unless you leave it to the last second where its leaking horribly all over the engine. And just keep an eye on the oil to get an idea of how much you lose per 1000 miles. With that information, you will know if its more serious or just slight.
'92 300CE - Sold
2004 C240 - C7 Wheels
2015 ML350 - P1, Pano, Ash poplar wood, Sport Dinamica interior, Running Boards Keyless go.