I actually kind of hope that when Taylor's clan gatecrash Sol, the Tenno's dad figure comes with.
No, not Umbra, though I can easily see him showing up. I mean Teshin. After getting a Tayno infodump, he'd probably respect Piggot. She obviously hates herself and whats happened, and detests her job and all it entails. Despite that, she shuts up, does her Duty to the best of her ability, and chokes down the indignation over what her life has become.
Though, if Taylor was the one that save Umbra, I don't think it's much of a stretch that he'd be the first one through the solar rail on a rescue mission. Entering Earth's atmosphere with nothing but a shield of pure wrath protecting him, cratering the parking lot to the dock leading to the PRT rig, and demanding to know where his Taylor is.
UMBRA: "You're he father."
DANNY: *terrified* "Y-yes."
UMBRA: *Puts a massive, talond hand on Danny's shoulder* "Be proud."
DANNY: "I am."
And then someone take a potshot at Taylor.