I think/hope this is just a miscommunication on where the two angles are coming from.
ABSOLUTELY be aware of/secure in what you're eligible for on the date you choose to retire. Retire confident in the fact that you're leaving with what you're comfortable with.
Absolutely do NOT feel obligated, in any way, to "help" your organisation. When push comes to shove, they'd lay you off with zero hesitation. They'd fire you without hesitation.
None. Never bend over backwards for them. You provide more to them than they provide you.
Now, the amount of "guilt" you feel for bailing on your co-workers is another story. But again, your company will survive without you. As will they. And there are many ways to give them a heads-up "off the record" if they're your actual friends.
But yes, I think it always went without saying that you need to be aware of your eligibilities before you bail... The rest (esp owing your company some kindness) is not and will never be part of my world. Give them the amount of notice YOU are comfortable with.
Signed,
Former Federal, Provincial and Local government employee