In Yekum Purkan, we pray for the well-being of the rabbis in Bavel, the Reishei Chalei, & the Reish Galvasa (commonly pronounced Galussa). This specific prayer for non-existent people and positions seems unique and I wonder why wasn't it amended? See for instance Tur Orach Chayim siman 188 that the language of Birchat Hamazon reflected various states of pre Beis Hamikdosh, during the Temple period, and following the destruction, by saying build, uphold, our rebuild Yerushalyim. Apparently, this type of amendment was not applied to Yekum Purkan. Why would we not care about uttering words that are not proper? (See Sefer HaChinuch 606 to only pray words that are applicable.)
Note this is not a prayer to return to days of old, but a prayer to uphold the situation as is, even though it doesn't exist.