You say:
and are well aware that I would pay for their care in this event.
I assume you mean that you would always pay it until they die. If that is the case, then Social Services would have no liability at all & there should be no need for them to have any involvement in your parents' financial affairs. If a Social Services assessment was done for their care needs they would be asked about finances & Social Services ought to be satisfied with information that you would be paying.
BUT I have heard that there can be problems with this if a third party (i.e. you) is making the payments rather than the person needing care. I do not understand why this should be, but it would be best for you to check the position with the local authority which controls Social Services in their area. You don't need to mention anything about their house - simply enquire what the position would be if they needed care and you undertook to pay for it because they could not pay for it themselves. It would be best to get this in writing.