I've never been absolutely dependent on Nav maps or maps that require cell phone reception. I simply review routes beforehand and in some cases have paper maps if needed. This is especially true in areas not eMapped and/or without cell reception - which would tend to include many camping areas and especially many areas in the Southwest and Rockies I've 4-wheeled in (not in the MDX). In some of these areas I've 4-wheeled on trails all day long without seeing another vehicle, person, or building - just the trail I'm on and the countryside around me.
The Nav can be handy when navigating around in unfamiliar cities but I rarely need it for getting between longer hauls due to pre-planning the route or even using street/hwy signage. Within cities the major routes tend to not change that frequently so I expect probably over 90% of the time maps that are even a few years old will work fine. There'll be occasional impacts due to brand new freeways, exits, neighborhoods but think back to how many times those really got you caught.
Also don't forget that the 'updates' seem to sometimes still not include areas that are a couple of years old - i.e. it's not like the updated mapping is comprehensive.
I have the original map in my 2014 MDX, built June 2013 (4 years old now) and I don't feel compelled to need to update the maps. In addition - it chaps my hide to have to pay even the discounted $99 for a map update when I know I can get free updates on my smartphone or on a Garmin. I don't like the fact that Acura (and others) have decided to make things like map updates a profit center for them rather than an included service for this premium vehicle that was purchased. It's kind of like a hotel - the more expensive a hotel is the fewer amenities are included and they charge for the services the less expensive hotels provide at no additional cost (wifi, parking, etc.).