2700 lumens at something like 100" is going to be ABOVE your typical LCD TV in torch mode ft-L rating. Imagine how bright the room would look with say a 50" LCD on, then imagine over FOUR times as much brightness.
In a dark room, even something like 300-400 lumens really lights it up. Go above 1000 lumens and it's almost enough to read a newspaper. Above 2000 lumens and you can have significant ambient light on and still get some contrast on the screen.
From what I can tell, you're probably looking at a maybe 80-100" image to provide some mood scenes? I'd say any older projector will provide more than enough light, and on any sort of business projector you're going to struggle to get the light output down to something that matches the ambience of the place.
BTW - that article exerpt is talking about the need for 2000+ lumens so that you can still watch video with significant ambient light. Ambient light raises your black level (since a projector doesn't "project black"), so you have to raise up the image brightness to compensate. If this is used in a dark setting, you don't want a ton of lumens, especially if it's supposed to be a subtle image on a frosted mirror or wall.