I think people are rather over reacting to part of what the government sais. I do not think they are talking about those over retirement age goig back to work. They are talking about those between 50 and 65 who have dropped out of the workforce.
I must say I am puzzled by the number of people between 50 and 65 who can afford not to work and who clearly will not get any benefits. I know one reason suggested was big inheritances, but the average house price in the UK is just over £300,000 and assuming 2 children, that is £150,000 each, a substantial sum, but not enough to support you for 10 + years - and you go into retirement when you could most need that money as a cushion, with nothing at all.
The same with early retirement. even someone in a very high paid job, is going to see their occupational pension slashed if they retire in their 50s. If you earn £100,000 a year and expect a pension of £50,000 if you work to retirement age, it could be slashed to £25,000 or less if you retired in your 50s, and while £25,000 is a large pension to most, for someone on £100,000 that is a 75% drop in income.
I suspect a lot of those not working are people in their 60s and close to retirement age, others will be part timers, especially older women, who discovered in lockdown that, with a partner still working, the household could manage with only one income. There is also the child care issue. Quite a number of members of GN say they ave given up work or shortened their hours when they became grandparents to provide child care.