Decided to make a thread since multiple people are experiencing this bug.
Revenant utility skills are randomly swapping positions with each other upon legend swap ( IE Say you have Impossible odds bound to 1 and Phase traverse bound to 2, the positions of the skills will randomly swap places so Impossible odds is now 2 and Phase traverse is now 1 ). It seems the utility slots are reverting to "default" positions and failing to carry keybinds with them. This can happen even in cases such as sPvP where switching utility slot positions is actually supposed to be impossible - which makes the bug very annoying since when this happens during a match you cannot fix it until after the match is over.
This bug is new and unique to the patch that happened earlier today, so something likely got broken in the midst of the bugfixes that were released for Rev.
After swapping skills on a legend, it will not swap them again if you just leave the new positions as-is instead of swapping them back to what you want after you are out of combat. Because we don't know how long it will take anet to fix this bug, it's far easier to just get used to using the default-keybind positions of your skills. You can also fix it by changing your keybinds to match these default-positions it keeps resetting our skills to. Took me about 3 sPvP matches to get used to. Far less annoying then hoping it doesn't happen and getting tripped up midfight whenever it does.
More information about how this reordering works was looked into by @Justine.6351 can be found here: https://en-forum.guildwars2.com/discussion/57025/i-know-why-legend-skills-reorder-now-not-random#latest
It seems skills are paired to each other based on their default positions. So if you reorder your skills so that the skills are in the same slot positions as their pair ( quoted below ), they shouldn't swap.
The skill pairings are (tested in game),
* Facet of Darkness/ Riposting Shadows/ Inspiring Reinforcement/ Pain Absorbtion/ Protective Solace
* Facet of Elements/ Phase Traversal/ Forced Engagement/ Banish Enchantment/ Natural Harmony
* Facet of Strength/ Impossible Odds/ Vengeful Hammers/ Unyielding Anguish/ Purifying Essence
Renegade coffee thoughts: https://en-forum.guildwars2.com/discussion/34989/major-renegade-rework-suggestions-thread