As mentioned on the main page, the Japanese voice actors for Fujiko, Goemon, and Zenigata (Miyuki Sawashiro, Daisuke Namikawa, and Koichi Yamadera) were recent replacements for the longtime original actors (Eiko Masuyama, Makio Inoue, and Goro Naya) who had been retired by TMS. note All three were getting on in years, which showed in their final specials. Indeed, Naya passed away less than a year after this series aired.
On the English side too, in a way. Funimation's actors for Fujiko and Zenigata (Meredith McCoy and Philip Wilburn) had retired, so actors from the "Red Jacket" cast were used instead — Michelle Ruff reprised Fujiko, and Richard Epcar took over for Zenigata.
Zenigata's an especially notable case. They were trying to find voice actors already familiar with the franchise. While having Ruff take up Fujiko again was a fairly simple matter, most of Zenigata's old voice actors weren't even in the industry anymore, either having retired or moved on to other things. Christopher Sabat, who voices Jigen in all of Funimation's Lupin dubs, admitted that it felt a bit odd calling up Richard Epcar, seeing how he played Jigen in "Red Jacket" (and directed it). Fortunately, Epcar likes the franchise and was happy to be involved in any capacity.
Role Reprisal: All of the main voice actors in the English dub had been in several previous Lupin productions, though over seven years had passed since the last dubs. Michelle Ruff is the notable case, as she reprised her role from "Red Jacket" despite not living in Texas. Richard Epcar is the odd one out – despite his significant history with the franchise, he had never played Zenigata.