however can it remain that way unattended with no worries that something will someday leak and destroy our 100 year old farm home?
It should not cause a problem.
Since you said that the filter was full of gack, that gack is coming from somewhere, I think filtering it out is a good thing but that is up to you.

There is never a guarantee that ice makers/ water dispensers will not leak.

My whole house has a water softener/filtration system. The refrigerator has a built in filter that is full of gack. I have removed the filter and there is no sign of leakage, however can it remain that way unattended with no worries that something will someday leak and destroy our 100 year old farm home?