In software development or maintenance it comes to a point where the language or tool you are using will become a roadblock and unable to keep with business demands, you left with two choices, continue to suffer with the limitations or update them current stable version(s).
In my opinion if it become an obstacle, bite the bullet and upgrade them. It may block your progress for short period of time, however you will gain the benefits in terms of faster development time, less language/tool related bugs and less maintenance problems. This also makes the software developers more enthusiastic and look forward to work on newer stuff. However upgrading comes with own cost such as compatibility issues, version mismatches and training issues. For any sizable enterprise you may setup tiger teams to evaluate the benefits and risks associated to upgrades and make a conscious decision.