Basically, the big change to Polymorph in the errata back around the start of the year did nothig whatsoever to Polymorph itself. What it did, instead, was to isolate the Polymorph spells, effectively quarantining them from the rest of the system. Now, other spells and effects - such as Wild Shape and any monster's shape-changing ability - which previously referenced Polymoprh have all been changed to work on independent game mechanics (mostly the revised Alternate Form rules in the Monster Manual).
So, you can choose to keep using Polymorph in your games, but if you don't want to, you can remove the spells completely, and so long as you're running from the errata'd rules, the rest of the ruleset is left intact.