I get the gist of what you're saying, but I'll nit pick a little with your projections.
Wilson just turned 27 (August) and will be 28 at this time next year when she heads to Paris. Four years after that in 2028-- at the next Olympics -- she'll be 32. In this day and age with advancing knowledge on how to stay in playing shape for longer periods of time, I think she'll be just fine. If she's gong to be a legacy, that will be in 2032. She'll be 36. I don't know how old you are, but I look forward to being able for both of us to debate "I told you so" at that time.
BTW, Stewie -- also born in August -- is two years older than A'ja. I think she'll be good in 2024 and 2028, too (and not on the legacy card). The one after that? Hmm.