I despise the "should" be advice more than any. My son started sleeping through the night at 4 months. My daughter until 10 months (although, now that I'm writing this and thinking about it, it may have been older). and both were appropriate for each of my children. my daughter still is a healthy eater with a high metabolism and needs to eat every 2-3 hours.
Since it sounds like you are giving him a bottle, what you could do is choose one feeding to feed him less and less. What I did was give one less ounce for a few days. then one less ounce for a few days until finally the one feed was gone. I think what I even did at one point because she still wanted to get up is I started doing half/half water & milk and then kept increasing the water and decreasing the milk until it was only water. She very quickly stopped getting up because she was only getting the water and it wasn't worth getting up for it.
One feed we got rid of by simply not letting her eat any more at that feed. She would keep insisting and we wouldn't cave. After a week or so she stopped getting up.
Honestly? In retrospect, I wouldn't do that second one again. It was painful for all of us, whereas by giving her less until a point then switching out to water was more of a gentle approach and not as painful with the tears.
Just my .02. As others have said, take it with a grain of salt.
The US is one of few countries that place such a value on that sleeping through the night where other countries on demand feed through the night until kids or 2 and 3. They also co-sleep as well. I'm not advocating one or the ohter, but some of our societal norms are simply cultural. It is not a biological necesity.
Take all the info and do what you think is best for your family. If you want to wait for him to out-grow it, I think that would be fine too. (you may want to stop talking to your other friends about it too! ;)