retrieve the tohwed hydrolocahtur...
 

Is there any disadvantage to having your array out? Any reasion to retrieve it

If you have to go backward or to maneuver wildly (evasion) you can cut it.

When going backward for sure. But no wild maneuvers will cut it. It's juist not implemented, even it is said in manual (same with torpedoe wires).
With DW 1.03 big depth change (from deep to shallow) can throw you going backward (that's a reported bug) and cut TA, especially in AKULA.

Also when situation gets dense with torpedoes, autocrew will report new contacts ALL THE TIME. It can cluter map with purple lines in seconds. Sometimes it is OK to turn sonar autocrew off, sometimes it is better to retrieve TA. On the other hand, TA gives good overview about your rear hemisphere which is good thing in torpedo evasion.

The biggest reason to retrieve it is that the water is too shallow. If you are slinking along the bottom or in very shallow water you need to pull it in because if you don't it will drag and be useless.