Here are the steps that led me to the problem:
I was able to record touch events on my emulator with Android 9.0 and x86 CPU/ABI. However, executing the replay_touch_events.sh script give me this output:
mysendevent: 1 file pushed. 4.9 MB/s (13608 bytes in 0.003s) recorded_touch_events.txt: 1 file pushed. 4.6 MB/s (15281 bytes in 0.003s) /system/bin/sh: /data/local/tmp/mysendevent: No such file or directory
As you can see, even if it pushes mysendevent in /data/local/tmp/ correctly, the script can't find mysendevent when it have to execute it.
I'm sure about the success of the push because of the output of adb shell ls -ls /data/local/tmp
16 -rwxrwxrwx 1 shell shell 13608 2020-03-26 08:10 mysendevent