Yes, and even that chart strongly indicate that the players are supposed to know the AC, as that is how charts are usualy referenced - look at the header and get the interesting number below. If the intention had been for AC to be hidden, the chart would have been inverted, with roll result on top, and AC hit below..
After all this all came from a competative wargame inspired table, and in those War games it go without saying that all stats of troops in the conflict is open information. I guess that intuition got lost somewhere along the line due to power hungry DMs..