It's not the lack of a face-to-face announcement that I find upsetting and disrespectful. I have been made redundant twice in my life; both times, the bad news arrived by email. Under the circumstances, combining a large number of redundancies in a single day and the necessity for social distancing, this way of communication is not inappropriate in itself.
What I find truly miserable and offensive about the letter is that it's written in a purely bureaucratic language, devoid of any sign of compassion or gratitude. Phrases like "please accept our deepest apologies for this difficult decision" or "on behalf of the company, thank you for your time and efforts working with us" go a long way in such a situation, even if whoever's writing them doesn't actually mean it. Being so lacking in simple human kindness and common courtesy on such a sensitive subject just adds insult to injury and makes the already terrible situation even worse.
My deepest sympathy for everyone who lost their job. I hope that you will soon find a good alternative and be happy and fulfilled somewhere where you will be treated as a living person and a valuable professional rather than just as another asset.