I can understand how Mr. Markle must be feeling. The papers were brutal about him and his home prior to the wedding, and that People article, with the letter paraphrased by powerful Hollywood stars, was also quite brutal. He is feeling hurt and betrayed and probably embarrassed and wants to set the record straight.
Thomas Markle is out of his depth. It's fortunate that during M&H's courtship the press pack was unable to locate him in Mexico. After the engagement, it's rumored that someone spilled the beans about his whereabouts, likely for money. It appears that Meghan had at some point informed her father about the relationship with Prince Harry (probably in advance of their dating becoming public). My opinion is that Meghan had reason to be wary of her father's behavior and reactions, and thus she probably did her best to cautiously keep him in the loop early on. We also know that M&H tried to prepare Markle Sr for the media onslaught. Even he admits M&H advised him not to talk with the media. Being portrayed in a less than positive light by the tabloid media is no excuse to betray one's daughter and her in-laws! It seems clear that Markle Sr not making more of an effort to attend the wedding, is not the first time he disappointed his younger daughter. M&H had encouraged Markle Sr to come to London two weeks in advance of the wedding, in order to get acclimated, comfortably situated, and fitted for a suit (had he done so, his health issues could have been looked after as well).
Although, Meghan only spoke about her father in a positive way on her Instagram and in other print reminisces prior to meeting Harry, there had to have been some discord in communication with her father during her teenage years. I suspect that the older adult children were peeved as they saw Meghan excelling and having the opportunity to attend an exclusive private school, and later a prestigious college. In addition, they surely resented Markle Sr spending time working on the lighting and stagecraft for all of Meghan's school productions, particularly when she was in high school. Meanwhile, Markle Sr was not around when the older kids were growing up. He'd left them and their mother to pursue his fortunes in Hollywood. Markle Jr, and Samantha (aka Yvonne) were teenagers before they had the chance to get to know their father. From all available evidence, it appears that Markle Jr and Samantha (especially the latter) have been good at manipulating and laying guilt trips on Markle Sr over the years.
Once the news of M&H dating hit the news cycle, the media began harassing and attempting to bribe everyone and anyone willing who were former friends, family, neighbors, co-workers, or former acquaintances of Meghan. The media hit paydirt with a few people. It's a shame that Meghan's father is apparently lacking in good sense and propriety, and that he's so easily manipulated by his older daughter.
Meghan's close friends mentioning existence of the letter to
People magazine was done to counter Markle Sr's mistruths. Revealing the existence of the letter and briefly stating the letter's intent is a far cry from selling or offering the actual letter to a notorious tabloid publication. Meghan's friends came to her aid in an atmosphere of OTT media negativity that was directed at Meghan throughout her pregnancy. The irresponsible behavior of the media in taking advantage of a weak and susceptible senior citizen who's related to the pregnant woman they have been intent on vilifying for clicks, readership, and monetary gain is utterly despicable.
It appears to be difficult in certain quarters to keep these 'royal' matters surrounding the Sussexes in logical, sensible perspective. But showering Markle Sr with overdone sympathy is sadly, yet definitely, a waste of time and effort. Trying to figure him out is also a sad endeavor. Suffice to say, it appears that he doesn't have good sense; his ego is outsized; he's easily manipulable by relatives and strangers who harbor devious self-interest; he can't be trusted; he seems to think he has a chance in hell of reconciling with his youngest daughter at the same time he wishes to exploit and extort the fact that she has married extremely well. This, all the while whining about wanting to see his youngest grandson when, from all appearances, he has no relationship whatsoever with any of his other grandchildren.
