I don't know what our generals (they are not Trump's generals) think about this.  Nor do I really much care,  Most current general officers - especially those at the highest reaches of the military - received their constellation of stars from the Obama administration.  It's no wonder many disagree with Trump on this issue. If there is a Deep State, they are part of it.
Officers at lower levels of command - the ones who have to deal day-to-day with personal relationships among their subordinates might have an opinion different from those at the top who spend more time dealing with politicians.
Surely most of them would not welcome transgender concerns to their list of on-the-job issues. 
They already have their hands and days filled with dealing with issues in the supposedly private lives of their troops:   fights between husbands and wives, alcoholism, drug abuse, dear john letters, potential suicides, DUII's, interracial tensions. ...   
Why would any of them want to add more issues?