Sorry, but this is rubbish. By your logic, if one joins a conspirative
gathering using a secret password and then is told than in future there
is a new secret passphrase, he would then be required to leave the room
again an reenter it using the new passphrase. There is absolutely no
security value in this, just a small entertainment value perhaps.
Reestablishing expired encryption keys clearly has a security value, due
to brute force issues on current connection keys.
But if somebody has brute-forced your initial shared secret to establish
the connection an you have changed it in the meantime, he will not be
more able to establish a connection if you keep that old connection.