As always in questions like this, lots of opinions flying around,few facts.
I would suggest the best way to answer the question is by experiment.
1. Create a AB map based on the MBT mapboards.
2. Create AB scenarios based on a few MBT scenarios
3. Directly compare the experience of playing the AB/MBT scenarios to playing the MBT boardgame.
I have done this a few time for different games, Squad Leader in Steel Panthers, WAW85 to Tac Ops, and a few others. It is a fun exercise though I don't know how meaningful it is.
I did the WAW85/TacOps scenatios abou 5 years ago and didn't take notes, so this is from memnory; World at War 85 is a platoon level armored warfare game, MBT counters are for single vehicles. Like AB, Tacops units are single vehicles or squads, though unlike AB, multiple units can be combined to be represented by a single icon.
1. The first obvious difference, the faster pace at which the game proceeds is well known, but has to be seen to be believed! A WAW85 scenario that might take 45 minutes to an hour to play will last just a few minutes in Tacops
2. The map area in the boardgame is smaller. If the maps are imported/implemented in a computer game, EVERYTHING on the map is within range, line of sight becomes critically important, and this feeds bavck into ther import/implementation of the mapboards.
3. Turn timescale: BG turn timescales/durations are usually quite vague, with IGOUGO turn sequence. Tac Ops and AB are both more or less continuous
4. BG sceanios are TINY compared to computer games scenarios. This is essential to make them playable.
5. BG map sizes are TINY compared to computer games scenarios. Tac Ops can go to 30km x30 km, AB is 15km x 15km, BG's maybe 3 km x 3 km
5. Weapon effects appear to be far more lethal in computer games. I suspect that in determining weapon effects at a given hex range, BG designers use a fuzzier range calc than simply no. of hexes x nominal hex size for reduced hit percentages at longer range.
It was a fun exercise. I imagine the results of an MBT scenario implemented in AB would be very similar.