What if... The USCSS Nostromo wasn't destroyed?

This What If will take a little while to explain, so bear with me...

As Alien fan's we are all aware of Special Order 937 which ordered Ash and MUTHUR to acquire a specimen of the Xenomorph from the derelict Juggernaut on Acheron LV-426, even if it was at the expense of the crew. Ash's frequent collations with MUTHUR is evidence of the two's conspiracy to follow the executive order to the letter.

In the theatrical release of the movie Ripley never explores the lower depths of the Nostromo, and as such does not happen across the bodies of Dallas and Brett, the latter of which is partly metamorphosized into a Xenomorph egg. Because Ripley does not happen across them and they are not seen, does this mean that their fate was simply death, as with Lambert and Parker, or was their fate the same as in the deleted scene just undiscovered and as such not incinerated?

Keeping within the confines of the theatrical release, while taking special order 937 into consideration with the possibility that Dallas and Brett remain undiscovered within the bowels of the Nostromo, MUTHURS actions later in the movie become questionable if we assume MUTHUR knows of Dallas and Bretts predicament. Firstly MUTHUR allows Ripley to activate the Nostromo's self-destruct sequence, potentially putting Egg-Brett in danger and contradicting SO 937. Later, after Ripley successfully shuts down the self-destruct sequence within the time limit MUTHUR ignores the command and continues with the sequence, much to Ripleys angst and definitely putting Egg-Brett at risk, breaching SO 937.

That is unless MUTHUR had a contingency plan...

What if after eavesdropping on Ripley, Parker and Lamberts plans to escape the Nostromo in the Narcissus MUTHUR initiated a secret protocol that would come into effect when Ripley activated the Nostromo's self-destruct sequence. The plan was simple - to eject the nuclear reactor core moments before the self-destruct sequence finalized, using conventional thrusters to move the Nostromo to the minimum safe distance from the blast, thus ensuring the survival of the Xenomorph specimen that former crew member Brett was becoming.

To surviving crew member Ripley, rocketing away from the detonation in the Narcissus would have only witnessed the blast with the Nostromo having been thrust in the opposite direction, and thus would assume the Nostromo destroyed. With Ripley drifting toward the core systems The Nostromo would drift past and beyond the Thedus mining colony. Powered down (due to no longer possessing a core) to ensure the survival of the Xenomorphs survival Bretts metamorphosis would complete uninterrupted, with a royal face hugger possibly using Dallas as a host for a Queen embryo.

Years later the Nostromo could then drift into a system run by a corporation other than Weyland-Yutani, the refinery within having become a throne room for the Queen Xenomorph born from Dallas, surrounded by a plethora of eggs.

Edit: Added images to clearly show the detonation of the Nostromo's core...