the apron to the northwest corner providing access to Pier 1 at T2 and the new remotes is additional. If all of T1 become remotes then those stands are the additional relative to before the TP. That assumes that Pier 2 and whatever happens where Pier 3 is planned and masterplan images show rotation of the stands, are not less than was before.
But, if parts of T1 are to be demolished, and Pier C is committed to be demolished as part of the planning for TP, then those stands would be lost at least for a period of time until replacements are built.
Overall, i would have thought that there will be a slight / very slight increase in stands over the next 2-3 years as all of this work finishes. And, i know that the TP will be 'finished' in 2025 but i'm assuming changes around T1 after that when i say that. Rightly or wrongly!