If this change is implemented, it would not mean that you are forced to perform the D check. You can still terminate the lease before the D check. It is just that you may have to pay some lease termination fees. On an old aircraft, those are peanuts.
This change, if implemented, is far less what Jona (and myself) would like to see. It is really a very minor change.
Let me give you an example. A 22 year old A320 may have a lease price of 250,000 per month. Suppose the lessor sets the minimum lease period that would take you 1 year past the D check. So at the time of the D check, your choice is to take the D check, and pay 7,000,000 or to terminate the lease. Lease termination fee would be 1/2 of 1 year lease of $3,000,000. Or $1,500,000. So if you really want to stiff the lessor, you can still terminate the lease, pay $1,500,000 and leave the lessor with a net $5,500,000 bill for the D check.
If you really despise the lessors, you may terminate on a day before the D check, so that the lessor does not have a chance to scrap the aircraft.