Fully cooked chicken tastes kind of weird
Without knowing what extra ingredients were added during manufacture, I'll make the assumption we are talking about plain frozen chicken, and no other additives could account for the pink juices.

You said the cooked texture was normal, but you found pink juices in the bowl. This suggests to me that the chicken was not fully cooked. It sounds like it wasn't that far off or else the texture would clearly be very unpleasant all the way through. Did you ensure the chicken was fully defrosted before cooking? If is was still slightly frozen in middle this could be the reason why.

Microwaving raw chicken can be a bit of a hit and miss affair, microwaves do not heat food evenly, which is why dishes should always be stirred part way through cooking etc. I would use a covered dish or plastic wrap to trap the steam and keep the meat moist. 

150C in a normal oven seems a bit low to me, I'd use 180C for 15 minutes, but it all depends on your oven. 

I like a bit of colour on my chicken, so I would be tempted to fry these in a skillet with some salt, pepper and butter over a medium heat for about 10 minutes, turning every so often. This may give you better results with this particular product than the microwave or oven methods. 

Chicken should reach an internal temperature of 75-85C (165-175F). If the meat splits easily with the blunt side of a knife that is generally a good indication it is properly cooked.