This was also Suda's status two years ago and the reason why he can't reprise his role as Philip/Kamen Rider W in Kamen Rider Heisei Generations Forever. It was planned that Suda will appear in the movie, but because his schedule was fully packed for the next two years that time, he can't reprise said role. Kamen Rider W will celebrate its 15th anniversary in 2024, hopefully Toei is smart enough to book Suda in advance.
[Source: @neet21_, Model Press via Yuki Kun]