Yes, protection against seasonal flu is definitely a sensible precaution for all travellers regardless of where they are travelling.
Respiratory infections account for over 25% of health problems while travelling, and you are three times more likely to contract a cold or flu. There have been well-documented outbreaks of flu on planes and especially on cruise ships, so a flu vaccination is a precaution that is well worth taking.
There is also the potential confusion with other infections such as coronavirus since symptoms may be similar. Therefore, protecting yourself against the flu with a flu jab is a simple and sensible pre-travel vaccination to consider.
Keep in mind that in tropical countries, flu is not seasonal, it occurs all-year round. Travellers to tropical countries are vulnerable to flu at any time of the year. And of course, in the Southern Hemisphere, flu seasons are 6 months out of phase with seasons in the North.