There's been (at least!) one already this year: Rick Springfield's The Snake King. Great bluesy tunes, savage lyrics & a voice that sounds forty years younger than it actually is. What a career renaissance RS is having!
The Mission from Styx in 2017. I liked it a lot, but I don't know if that's what the OP meant by 'truly great'.
I haven't seen any mention of it (though I'm not exactly in the loop these days on a lot of this stuff), but this month is the 20th anniversary of the Neutral Milk Hotel In the Aeroplane Over the Sea release in 1998, wonder if anything is planned.
That's the only one I can think of. Much great music is released, but not lots of great albums (collections of these songs.)
Four albums I listen to from the last 15 years, I think there are very few others but given time to think about my feelings I might conclude all of these are great.
A few to add to the list: My Morning Jacket - Z Tedeschi Trucks Band - Revelator Dr. John - Locked Down
This statement doesn't make a whole lot of sense, to be honest (regardless of how many times it's been pointed out). Some people just get older and stop listening to contemporary bands, or only like certain modern songs over entire albums. That doesn't mean they "don't like music" or only like a "couple of bands". It would be like me telling someone like you that you might be a "music fan", but you don't actually understand what makes for a truly great album.
Courtney Barnett- Sometimes I Sit and Think, and Sometimes I Just Sit Kendrick Lamar- To Pimp a Butterfly
Not true. I'm 41 and still looking for new music. I would agree that I am not quite as open minded now as I was 5 years ago, but the sheer amount of music running around in my head makes that a survival mechanism.