You are interpreting the mappool wrong. With 1600 ladder rating you will have 13 maps in your mappool. The misinterpretation is not your fault, the announcement post of the new pool contains an error. It should have been mentioned that you get maps from your own bracket + the bracket below that.
Consequently that means ~30% of your maps will be 20x20 and the rest will be 10x10.
Bermuda Locket and Crossfire Canal are indeed somewhat on the high side in reclaim. The reason for their inclusion is that there are not many suitable alternatives that allow for navy play for 1v1. But I agree that it is not optimal, considering the parameters that were set for this new format. If you have suggestions for other navy play maps for 1v1, that are more suitable, let me know.
Last, I don't think it was ever the intention to exclude 20x20 maps completely from this 1v1 trial format, but I understand your confusion, now that I reread Arch's announcement.
I agree that 30% 20x20 maps might be a bit much. Perhaps we can remove one.