We have been told that the policy is now that HR24 is replaced with same. If that is the case, then it should be for the 44 as well.
That is replacements not upgrades, with replacement if the receiver fails than you get the same model (either free with PP or $20 shipping without PP or they waive the fee) but with upgrades you get whatever they have available, What usually happens is if its self installed and they ship it to you, you might get refurbished older box or similar to the HR22, it could be a HR24 if you're lucky, now if its a truck roll and a tech is installing, depending If they have HR24/44 available in stock then there's a chance you get a 24/44, but it varies on what the installer brought with him.
Directv HD DVR HR44-700
Directv HD DVR HR24-200
Directv HD Receiver H24-200
Directv HD Receiver H24-200 Owned
Directv Standard Receiver D12-700 Deactivated
Directv Subscriber from 2009-???