All things considered, Gurira’s casting in Avengers: Infinity War sounds like fantastic news for her and her fans, not a reason for Walking Dead viewers to start preparing for Michonne’s untimely demise.
If that’s the case, filming probably wouldn’t affect her work on The Walking Dead in any major way.
Conversely, we don’t actually know how much of a part Gurira will have to play in Infinity War.
The movie is already set to be filled with the biggest heroes of the MCU, and Okoye might only appear briefly.