It was Father’s Day here in the US yesterday too.
The letter was probably sent by email, hard copy to follow (hence why unsigned).
Correspondence from the RF is an art in how to say next to nothing and letting the Royal insignia do the talking. This is no different, although with this couple the insistence on using a logo/symbol that so much as hints at royalty is ludicrously petty, coming from a couple living in splendor in Los Angeles after flouncing off out of the RF so publicly and bitterly. It only serves to bring to mind the “HMQ doesn’t own the word ‘Royal’, you know, and Harry remains 6th - SIXTH - in line to the Crown”.
That said, it looks like the meals that were delivered were prepared by The Hub, the effort MM got involved in and, IMO, did an excellent job with (as she did with Smartworks). I’m sure she is rightly proud of the workers and the contribution they made, and if she felt a letter from them would be well received, good for them sending it. (Still don’t see why it was made public, but oh well). Not being serving members of the RF I’m unclear what standing Harry and Meghan have to speak so authoritatively on behalf of people in the UK (and indeed the world over) about the impact of Covid-19 on people’s lives, but there you go.