Yea I decided to let mine leak for a year. I paid a shop to re-gear to 5.13s and had them replace all inner axle seals and rear bearings at that time. Cost basically nothing at that point.
As long as you monitor your diff fluid levels and change fluid after sever water exposure, your jeep will survive.
If you want to be sure it’s a leaky seal, leave your axle flexed that way overnight. You’ll see a little puddle on the ground in the morning.