So, like, if this is true... what are the possible things that could happen?
Very Unlikely - Obama invalidates election results, declares martial law, resigns, installs Biden as President until next elections can be arranged.
Unlikely - Trump impeached sometime after inauguration, Pence installed as President
Unlikely - Trump impeached sometime after inauguration, Pence not allowed in succession because he was part of ticket while Russian collusion was happening. Paul Ryan presidency.
Most likely - Trump is president for some length of time, potentially for 4 years, unless some other scandal arises that results in impeachment.
If this is verified though I do not see how Trump/Pence can win reelection in 4 years (they would have to have insane balls to even run again and I don't see how the GOP establishment would even allow it, they will literally pay them $ to not run again), so at the very least we may get that result out of this.
McCain a national hero in the history books forever regardless if this is true.