Uranus ♅ Troposphere ♅ Stratosphere
Thermosphere ♅ Exosphere ♅ Outer Space

109 "A Time of Shock! True Identities Revealed to One Another"

At the end of this episode, Haruka and Michiru speak about what happened. Haruka comments perhaps they shouldn't have transformed back during the battle. Michiru says if they hadn't, they would have lost their lives.

There was more to it though. She admits she wanted to help Sailor Moon and the others. This goes in hand with when Neptune suggested telling the other soldiers everything about their mission and work together in episode 96.

While some would say Michiru is more sympathetic and trusting, I think Uranus's objection to such is more out of protective reasons. As Uranus she often tells the others to not ask unnecessary questions or delve into things beyond their understanding. Like how Michiru had been towards her before her awakening as Uranus, I believe Haruka is doing her own version of that for the others.

As in her vision, Neptune told her the only ones who could do their mission was them alone. She and Michiru have vague memories of their past lives. There is chance that Haruka remembers just what sort of soldiers they had to be. They were ones with stronger powers who fought at a distance, unknown of and alone.

Moon's group would never understand their tactics or have the heart to tolerate them. If they did, they would have the same miserable duty Haruka and Michiru endured. Haruka was certain that the others wouldn't be able to sacrifice anyone. She wasn't going to ask for them to. Then by seeing how they reacted to what she and Neptune were doing during battles and hearing their thoughts about their harsh tactics and objectives... Uranus knew. They would likely never understand each other, so she wouldn't bother. She was sure she and Neptune could do it by themselves. It would be their burden alone.