Do both tricuspid valve stenosis and regurgitation result in hypertrophy in the right atrium?

Possibly: Tricuspid stenosis is more likely to cause hypertrophy (thickening) of the right ventricle, whereas tricuspid regurgitation is more likely to cause dilatation, where the chamber increases in volume without much thickening.

Sort of: The right atrium tends to enlarge somewhat with both conditions; it is more so with tricuspid stenosis. Technically though it is an enlargement, not a hypertrophy (which means muscular thickening). Ra enlargement with tr would imply either severe tr or very elevated pulmonary resistance pressures.