Celebrimbor

[Maédhros]

From the Shibboleth of Fëanor

Elenwë her mother had no Sindarin name, for she never reached Beleriand. She perished in the crossing of the Ice; and Turgon was thereafter unappeasable in his enmity for Fëanor and his sons. He had himself come near to death in the bitter waters when he attempted to save her and his daughter Itaril, whom the breaking of treacherous ice had cast into the cruel sea. Itaril he saved; but the body of Elenwë was covered in fallen ice.

If we are going to take this into account, (and I don't see any reason as to not use it), it seems to me somewhat improbable that Turgon would have allowed that Celebrimbor being descended from Fëanor into Gondolin, knowing his enmity for Fëanor and his sons.