The phrase "catching up with" can be replaced by many other words or phrases depending on the context. For example, in a casual setting, one could say "getting up to speed" or "getting back in the loop". In a professional setting, one might use "getting up to date" or "catching up on the latest developments". Synonyms for "catching up with" could also include "reconnecting with", "rejoining", "meeting again", or "catching up on missed opportunities". Ultimately, the choice of synonym will depend on the specific context and the relationship between the people involved.