Yes you can - technically is is possible, but there are some things to note if you wish to do this:
As the feta mould is different size (bigger than our other moulds) the cheese will be flatter and wider, so this could affect the speed of mould growth etc and you should keep an eye on that.
After using the mould for Camembert for example, you will need to sanitise the mould very well so there's no cross contamination in future. This would not be as concerning when using the Feta moulds later for Feta, but more concerning if the other way around, as you might have some bacteria present which, when encouraging mould growth - might develop and be unwanted.
Regardless of cheese made/size mould used - you still need to be careful there is no bacteria or mould spores affecting whatever you use the Feta moulds for next.