Does Happy Chaos have the ability to tamper with time or have some form of time travel more or less? He does recall meeting Axl Low in 2192, if I'm right, and somehow he was able to send a message to Axl Low in XRD, trusting him to deliver it to Asuka, regarding the events related to the Conclave.
Those events may not necessarily be related to any such power.
While it's true he has a strong connection with I-No, there's currently not evidence that he himself tampered with the Timeline like she has.
Also, because of what Axl Low explained previously, any changes to the Timeline erase the previous one, so there would be more evidence to indicate it.
Most likely it's the case that the "Sage" in 2192 that met with Axl and gave him that coded message to Asuka is not the same "person" as Happy Chaos.
The reason I can say that is because prior to Axl Low's involvement, the timeline took a different result (related to the Universal Will defeating mankind via the Valentines).
This is the "drab future" that I-No encountered (the one where Sol Badguy's power encroached him, turning him in to a giant Gear, Sol was actually "taken" to that future to see it himself by I-No, in Xrd Sign's events, but because he didn't know how to process seeing a giant version of himself, she sent him back).
Most likely Happy Chaos did not "exist" in that Timeline, but was somehow a "phantom" of the Sage who was outside of the Universal Will's influence.
But because of both I-No and Axl Low's interference of events, the Timeline changed and the result created Happy Chaos.
Since I-No had access to that "bad future" she was able to transfer that information to Happy Chaos himself.
That's why he could say he "met Axl" in the future, despite not being as himself in that era.
Or, alternatively, I-No's powers simply retained the ability to recall memories from other timelines, which is something that perhaps Happy Chaos inherited from her power.
Later on, in Strive's events, it's revealed that I-No saw Sol's fate in 2192, and relayed that information to Asuka in addition to the message he received from the Sage.
As a result, Asuka resolved himself to remove the Flame of Corruption from Sol's body, to save his life before the encroachment would occur (which is why Sol says "mind your own business" to Asuka).
So, if Axl Low hadn't relayed that message, Happy Chaos would never have been created in an absolute sense (well, technically he existed INSIDE the Universal Will, but he was never pulled out in any previous timeline by I-No herself).
This is also why I-No says that what she's doing is "Creation" not "Destruction" when she speaks to Ariels just prior to pulling Happy Chaos out of her body.