No, unless the engine speed increases excessively (in an emergency you will accept this for braking). Just about any vehicle will deny kickdown if your road speed is too high "at that time". It will put stress on your drivetrain, but this should be well within design parameters.
For a long steep descent in a heavy or overloaded vehicle, there may be issues with richer mixtures but this will depend on the delivery method and the age/condition of the components concerned. Keeping it on or above the redline will shorten the life of the engine, timing chains may stretch, valves may "float". If you have worn valve stem seals you will suck in some oil which can foul plugs and clog exhaust components (mufflers, ceramics, catalytic converters).
But in your case, the intent is for the shift down to occur so that the engine is not "lugged" and that more power is available. It is normal, many drivers would even preempt the shift to avoid the delay and perceived "shock".