For starters, I’m a licensed plumbing contractor, and I’ve installed miles & miles of PEX and CPVC pipe.
If your whole house was replumbed, it’s either PEX or CPVC. CPVC is different than PVC in that it is rated for use in hot water piping as well as cold water piping. PVC piping may not be installed in the water lines within a dwelling.
CPVC piping will definitely give a plastic taste for a while when the pipes are new. It may also give off the taste of the glue as well. Any time I replumb a home in CPVC, I always recommend bottled or filtered water for a month or so. Just for the taste factor, it’s not palatable IMO.
PEX can also leave a bit of a plastic taste, but MUCH less than other piping systems. It will go away over time also. Some of it is chemicals from the extrusion process, some is stuff picked up in shipping & handling, some is just plastic pipe taste.
To tell the difference between CPVC and PEX, simply look at the pipe. CPVC will be assembled with glued fittings and normally with a yellow glue. It may also use an orange glue, but most plumbers are too lazy to use the orange glue since you have to use primer before the orange glue, and the yellow glue is a one-step glue. PEX piping is either clear or colored red (hot water) and blue (cold water). They’re all the same stuff. There’s no difference between the red & blue piping, so if they switch it, don’t worry.
PEX piping & CPVC piping both have advantages and disadvantages. PEX is typically a quieter system, less prone to freezing, easier to install in an existing home, cleaner to install (no glue required), and is flexible. CPVC is cheaper and since the fittings go on the outside of the pipe, there is less pressure drop across each fitting. The inside diameter of the pipe is bigger as well, since the pipe wall is thinner than PEX.
If I were building a new home, I would install CPVC. If I were retrofitting a home, I’d use PEX.