Postgres: any traps when adding tables with `timestamptz` fields, when existing tables all use `timestamp`?

Similarly as in https://dba.stackexchange.com/questions/134385/convert-postgres-timestamp-to-timestamptz , but with the difference that I _don't_ plan to modify existing table's timestamp columns. **Are there any gotchas when using timestamptz for *new* tables, when all the existing ones use timestamp?** Presuming that the existing clients will continue to use the DB as thus far (by always converting timestamps to UTC on their end), is there anything else one should consider?