yes indeed they do (both points)
Any map could play very different as easily as swapping some weapon placements and adding a forge bridge or something
When gameplay is your metric, where is the line of what constitutes a "new" map? During the Infinite flight, were the weapon variants of Live Fire different maps?
Defining distinct maps by gameplay gets a little messy when forge and re-used geometry
blur that line (which is why I said the count for halo 5 is kinda annoying if you're trying to compare it 1:1 with older halo game counts)
Ultimately
for my count I chose to define a
distinct map worthy of 1 whole point in my count as each being one wholly original developer creation.
A remix largely reuses an existing map so that's worth like half a map point in my count, when in the context of being compared to prior halo map counts. I don't think a H5 Eden should count the same as a H2 Sanctuary.
Ultimately I did defend your count! If you just want a straight total count, in a vacuum, that's indeed 23 before forge.
Remixes just count for less in mine, because comparing a count that includes remixes to older halo games before remixes existed isn't quite apples to apples.
I did include Warzone in the count because that mode was meant to be 343's equivalent replacement for BTB. So for comparison's sake, that's how they're counted. Even though we all know in our hearts that Warzone was absolutely not an acceptable replacement or equivalent.