The irony here is no I don't think you should change it if it is recognisable but I definitely do think you should update it.
Of course what I also believe very strongly is that it is entirely up to you whether you change it or not. Your shout and your perogative.

BtG
There is never a good reason to change a logo unless something unsavoury has happened and you are forced to distance yourself from your earlier market and company.
However, if I did think about changing a logo, I would consult others in the club, ask the advice of friends I trust, bat it around the dgs like this and likely run a poll on the various options. I am sure you have done the same when making a business decision that will effect your employees, distributers and clientele.
It is a ABC rule in any organization (be it business, government and even religion) big or small, to research any decision that effects your image. That is how it is done..whether you hire a fancy consultant, call a Ecumenical Council, a town hall meeting or casually drop it on the 17th tee during a round of golf with your biggest client to see whether he reacts by hitting you with his Calloway.
I have owned many cars and I am sure you have as well. Every week we get requests, even from those we don't own any more, asking for feedback and comments on everything down to the seat warmer and trip meter.

I cannot imagine them acting wisely in any other way.
On the other hand, those who don't seek feedback get out of touch and make mistakes. For example, as noted here by the Aero owners in an earlier thread, the product changes so fast and inexplicably that their purchases are dated when they are made and their residuals suffer.
The only businesses that do well on non-consultation are soap operas. Would my dear Audrey watch Cornation Street if tommorrow's show was predictable? Soap operas thrive on shock value. Automakers do not.
There is no evidence whatsoever here that the MMC consulted with ANY of the players and constituents of its world over the last months on this decision. That fact speaks to a scary business vacuum at the top.
In any event, what we can all do (while wishing them well) is grab some nuts and a beer and watch the ongoing episodes of "Pickersleigh Road".
Lorne