Tapping into a well line?

[Valveman]

So does this principle apply to above ground shallow well jet pumps as well or strictly deep well submersible?

Above ground jet and centrifugal pumps are also made for continuous duty. However, these motors have ball bearings instead of a Kingsbury. With a grease cert and a shot of grease every year those bearings will last forever as well. But they no longer put in grease certs and use sealed bearings on most small motors these days. Sealed ball bearings have a posted number of hours they are made to survive. Better bearings last longer than cheap bearings. But the sealed bearing thing is because no one wants to do any maintenance anymore, and also supplies the planned obsolescence date the pump manufacturers like.