I am sorry to tell you, the answer is YES, this is a sign of thing to come, let me tell you rthe reasons.
First, adding multiplayer means they can also add ONLINE PASS, thus fighting the sales of used games
Second, if the game has a multiplayer component the people will take longer to sell the game back to a store like Gamespot
Third, With multiplayer is very easy and cheap to create DLC that brings more revenue for the company
Fourth, With multiplayer your friends will add peer preassure so you buy your own copy instead of waiting for somebody else to finish the game and lend it to you
There may be more reasons, but as you can see from a bussiness perspective makes a lot of sense.