Does this combination of the progressive and 'will' sound OK?
When we are getting old, we will become forgetful.
Even if the auxiliary verb were different as this, would it still sound a bit awkward?
When we are getting old, we might become forgetful.
Please be aware that I'm neither a native English speaker nor a teacher.
"fuhgeddaboudit " 1. Forget about it - the issue is not worth the time, energy, mental effort, or emotional resources. (Urban Dictionary)
I'm just wondering how you native speakers would make a predictive statement about two things changing and synchronizing each other.
When it comes to such prediction, will you say to yourself 'uhgeddaboudit'?
If you will, then it's fine with me.