The second pot is a display pot. When I use those for a time after I get a new Phal, I take the plant in its smaller pot out, soak it for a time, let it drain thoroughly, then put it back in the display pot. The display pot can cause rot if you aren't really watchful or if you over water. So can the moss pot inside it.

The little plastic pots they come in are designed for greenhouse growing and generally are not suitable at all for home growing. I find I usually go up to a 3" pot if the roots are still healthy in the 2" they come in. I usually just cut the plastic pot off, soak the roots and gently untangle them. They are going to be shocked by the re-potting, no way around that. They have grown to thrive in the greenhouse and orchid roots actually develop for the conditions they are grown in. They is why you generally prefer to re-pot when new roots are actively growing, so they can adapt to the new conditions. The old ones will mostly slowly die. Your new plant will be a year or so recovering before it's likely to grow well and bloom again. Those Phals are sold basically to be used as long lasting cut flowers, rather than to be grown on.

So, yes, re-pot if the Phal is struggling, has rotten roots in the moss, losing leaves, etc. If it seems stable I just watch it closely to see how its doing and re-pot when its done blooming. I put them in either terra cotta orchid pots (I find the 3" ones just about perfect most of the time for those Phals), or, if I have a small ceramic one, I might use that.

Hope that helps!