It has long been a debate even when the current pandemic did not exist or even considered. Is working from home provide an added motivation to be more productive or even a nuisance due to unwanted or unexpected distractions?
I guess this would boil down to several circumstances and I’d like to tackle those as much as I can.

Working From Home As Motivation

There are several instances that an employee would get motivated in giving a mandate to work from home as an option and these are:

• The employee gets to feel empowered due to (significantly) lessened travel time going to/ from work. It is a well-known fact that rush hour traffic jams can cause stress and even rage (I want to blame the mentality of getting ahead every single time because of rush hour traffic). With this saved time scenario, an employee would be able to enjoy this and most probably get motivated to work!
• The employee gets to have more chance to save more money. In relation to the first point, this instance will also make employees feel empowered as they would actually save money by not spending for commute. Talking about added perks!

• The employee gets to have a chance to work remotely – as in work to where he/she wants to be. Whether by the beach or on top of a mountain (or even a remote island), as long as there is a stable Internet connection, employees will enjoy this on a WFH set-up with their work.
• The employee, if have a child or someone to take care of, can do multi-tasking by working on the clock and at the same time attend to their children’s / family’s needs in parallel. Just an example would be that they can make milk bottles during their bathroom breaks or even change their diapers while listening to calls. What a wonderful use of time isn’t it?

On the other hand, there are also instances where a Work From Home set-up would be a nuisance and these are:

• An extrovert employee would probably be the ones who are affected specially when they are used to do some chat time for a minute or two with their colleagues. Though this can be done remotely, I guess doing it face to face would be the best thing.
• An employee would get distracted and affect their productivity from unexpected disturbances at home. A crying baby or even someone knocking at the door would easily distract someone.
• Do note that the upfront nuisance are not included on this list such as workers in a manufacturing plant or even a construction worker.

These are some of the valid reasons why a Work From Home set-up would be a motivation or even a nuisance. There will be cases that it would be for the better and even worse.
But whatever it is, it would always boil down to how an employee would react / adjust to the set-up and it can be measured by how they perform on their assigned tasks.
In terms of letting employees have the option to work remotely or at the office, it would be the prerogative of the company with the bias for the benefit of the company.
If the employee retains their productivity (or even improved) when they are working remotely, then by all means let them. Otherwise, take that incentive and offer it as a motivation to be more productive in the future to avail it again.
Things have changed in actual and the current health situation have proven that people can be flexible (and most probably adjusted) to the new norm. It just happens that going back to where they were would now be harder to swallow and accept again.