The Korban Pesach was made to be able to keep a meal in order to hold a celebration which serves as a remembrance (Shemot 12:14, 16).
A remembrance of the moment we took a lamb and used it's blood to make a sign upon the the posts of the houses in which it was eaten, so that HaShem could skip those houses and they would not suffer the same destruction that was caused in the other houses, which would lead to the eventual Exodus.
These days we can't bring the Pesach sacrifice, because there is no Temple, but we still hold a meal in order to hold a celebration as a remembrance. So that part still stands.
But does this mean that the command (Shemot 12:44, 48, Bamidbar 9:14) of circumcision (which would allow one to join the meal of the Korban with the matzot and maror) now without the Korban becomes invalid? (So one could join in a uncircumcised state).
The fact is that one still joins a meal which is kept to hold a celebration as a remembrance, and serves the exact same purpose, wouldn't it therefore be more appropriate to keep this command although the meal doesn't involve a Pesach sacrifice.