In the paragraph: https://www.postgresql.org/docs/current/ddl-partitioning.html#DDL-PARTITIONING-DECLARATIVE-MAINTENANCE, sentence "Another option that is often preferable is to remove the partition from the partitioned table but retain access to it as a table in its own right." there is missing "not" word. Correct form of this sentence should be: Another option that is often preferable is to not remove the partition from the partitioned table but retain access to it as a table in its own right.
The existing wording is correct. The fact it immediately precedes a detach partition command example should make this abundantly clear. Though adding “not” as you’ve done doesn’t make any sense regardless - it is a self-contradiction to both be a partition and independent (on its own right).