That TFR is mainly for the general aviation flying under VFR. As you are in class A airspace when you fly above FL180 there is a good chance that you have to look out for a different NOTAM.
There is indeed the active NOTAM A2831/22 covering that launch including detailed rerouting information for dispatchers. Just search for ZMA A2831/22 in the FNS NOTAM search (don't forget to change the "Location" pulldown to "Free Text") and see for yourself.
So, in summary, most TFRs are below FL180 as they are issued for:
- Temporary Flight Restrictions in the Vicinity of Disaster/Hazard Areas (Section 91.137);
- Temporary Flight Restrictions in National Disaster Areas in the State of Hawaii (Section 91.138);
- Emergency Air Traffic Rules (Section 91.139);
- Flight Restrictions in the Proximity of the Presidential and Other Parties (Section 91.141);
- Flight Limitation in the Proximity of Space Flight Operations (Section 91.143);
- Management of Aircraft Operations in the Vicinity of Aerial Demonstrations and Major Sporting Events (Section 91.145); and
- Special Security Instructions (Section 99.7).
(Source: AC 91-63D)
Those events rarely extend above FL180. When they do extend above FL180, as in this case, a separate NOTAM is usually issued which contains way more information that is normally only interesting for IFR operations.
Imagine you planning a local fun flight along the coast. Do you really want to wrestle with all those IFR NOTAMs during your preflight?