Why would they have to add anything other than parry/deflect to a game about parry/deflect. That's the game's main mechanic along with posture, and arguably you can defeat anyone just using normal block, evasion and attack.
Furthermore, evasion based games can have pretty hard evasion timings too, so it's the same in the end. In Sekiro you're timing one button press in response to enemies attacks, the only difference is your own animation and the fact that you can also evade in addition to block/deflect. So there are options. Plus: you can run like mad, while locked on, which would make any other souls game easy as fuck. Also, there are at least two prosthetic tools aimed at people who can't time the parries and/or evades properly. Of course they cost emblems because why the hell are you playing a rhythm have if you can't rhythm.
And what the hell does that have to do with this rumor.