Of course, the difference, in this case, is that an imitator was brought in to completely impersonate Pleasence, rather than get someone like Malcolm McDowell (who played Loomis in the Rob Zombie Halloween films) to do the lines.
Specifically, over in the Star Wars franchise, The Force Awakens brought prequel actor Ewan McGregor back to recite some of Obi-Wan’s lines during Rey’s vision scene, blending his vocals with the vocals of the late Alec Guinness to convey words spoken by an older Obi-Wan.
The way David Gordon Green explained Halloween’s use of Donald Pleasence’s voice in his recent interview with Yahoo Movies is arguably somewhat similar to tactics used by other nostalgic films in past years.