(a) Yes. (b) No.
There are tax savings when you reach retirement age (65) in Canada. However, there are also hidden increases in taxation at that age as well.
The savings are clear on the annual federal income tax return. The are the age credit and the pension credit. Also seniors are more likely to qualify for disability credits and medical expense credits. However seniors that saved for their retirement need to be aware that they can be excluded from the age credit and that they can have a repayment of old age security which is effectively a tax on wealthy retirees.
It can be quite challenging to manage the taxation of a retired couple. There are tools that can help like timing of retirement savings withdrawals and allocation of pensions using pension income splitting; but these take analysis and long term planning to optimize