What is the use of AbstractPikeman class?

It’s a leftover? or they are affected by some specific tech that I didn’t find?

Its a new tag in DE, not sure what its used for but perhaps it will be used for specific upgrades in the future. With african DLC coming i can see them having pike specific tags.

Abstractpikeman has been used in the legacy version too.
its just for the visual that the small info when you hover over a pike unit sias " pikeman´,

Here is a lsit of tags that are in the game ( LEGACY ! ) Unit tags - Google Sheets