This question depends greatly on the plant species involved and in what conditions they have been grown in. Different plant species have different abilities to acclimate to high sunlight levels which depends on their genes. Shade plants are specialized for low light conditions, and don’t have the genetic „programs“ which can allow them to acclimate to high light levels. So, shade plants can be damaged by direct sunlight under any growing conditions.

On the other hand, sun plants are able to grow in full sunlight without any problems under normal conditions. However, they might still experience negative effects if the amount of sunlight hitting them is more than can be used for photosynthesis. These plants might experience high light stress under conditions like drought, because the maximum rate of photosynthesis is less.

The past growing conditions can also have an effect on the potential for experiencing high light stress. If you have a plant which has the ability to grow in both shady and full sun conditions, it will become acclimated to whatever environment you place it in. For example, the number, size, and shape of the leaves might be optimized to the current growing conditions. On the biochemical level, the amount of xanthophyll and chlorophyll will also be optimized.

If we grow this hypothetical plant inside, it will acclimate to those conditions of low light using some of these methods. If we then suddenly take it outside in full sunlight, it could very well experience high light stress before it fully adapts to the new conditions (consider things like leaf shape/number would take a long time to change).