What the store discloses
The notice lists a limit of five different PC activations within a day. This is an activation disclosure, not a claim about five save files or five simultaneous players.
What we cannot conclude
The notice does not prove a performance penalty, an always-online requirement or a future removal date. We have not benchmarked the DRM. This finding applies to this Steam product, not automatically to every older Onimusha game.
Questions, answered
Is Denuvo confirmed for every platform?
No such claim is made here. This article documents the Steam PC disclosure only.