MEC is a great organization in terms of ethical sourcing, environmental responsibility, etc. and although they have some amazing prices on some of the gear they offer, they are NOT a military oriented equipment source.
The core purpose of Mountain Equipment Co-Operative is "to help people enjoy the benefits of self-propelled wilderness-oriented recreation...by selling outdoor gear, clothing, and services." As such, whilst some products have benefit for military use, that is purely coincidental, as providing equipment for military purposes (i.e. clothing in tactical colours, camouflage Petzl headlamps, etc.) is not part of their mission statement. If you're going to shop at MEC, great, just be aware that your money spent isn't going to sustain a business whose interest is in offering you a wide variety of tactical equipment and other field accessories from a military user standpoint. The black Petzl headlamp you just bought may only be offered in orange, or red the next year, as the purchasing staff has no incentive to consider whether the products they carry have any bearing on whether they can be used in a military context or not. A prime example is the Therm-a-rest Z rest; this product was quickly gaining popularity amongst troops as being an ultra-lightweight and very compact sleeping mat. Cascade Designs decided to discontinue the green, mil-friendly colour in favour of bright pumpkin orange. Do you think that MEC for one second considered whether or not the change in colour would affect the functionality of that product from a military standpoint? They provided no pushback to Cascade Designs, saying "Hey, lets keep the green colour, as most civvie hikers couldn't care less about the colour of the mat, but we do sell alot of these things to Army guys. If the mat is orange, the Army guys won't be able to use it."
If you are interested in being able to buy more tactically oriented stuff, and would like to be able to do so in the future, why not have a look at some of the 'military friendly' shops like One Shot Tactical, Dave's Army Surplus, Seals Action Gear, etc. and of course...the friendly staff at CP Gear/Wheeler Accessories. ;D