Maybe somewhat late to the party, but I also confirm this is possible. Just did the same with my non-retina Mid 2012 MacBook Pro 15 A1286 - bought a matte hi-res display assembly from a 2011 A1286 and did as it was described.
I even invented a slightly better way of locking the display connector. The retaining metal clip is mechanically incompatible, but just slightly. When I filed down the two protrusions at the edges of the horizontal part of the clip (it is thinner in the middle where the black tape is attached and thicker towards the edges) by about 0.2mm, I was able to push it all the way around the motherboard connector so it locked around it perfectly and securely, without the need for anything else. When filing, I accidentally slightly damaged the black tape so I rather took a piece of thin tape and sticked it around the black one to make absolutely sure it will not short out any of the connector solder joints which the retaining clip is nearly touching.
And if I did not want to re-sell the original 1440x900 display as a spare part, I would just have taken the retaining clip from its connector and mounted it onto the "new" one - the clips are of course detachable.
Anyway, I am eternally grateful to CTurns for his report which encouraged me to try it as well. The glossiness of the original display was bugging me for a long time, along with a subpar resolution. Now the MacBook is not in regular use anymore but I will still benefit from the upgrade, it was well worth it.