I'm sorry, but if your testers are not comfortable getting involved in the early design stages of your software in a 21st century world, then there's at least a 90% chance that their primary role at your company is perpetuating organizational dysfunction.

Most of my career has been defined by cleaning up the gargantuan messes the culture of "throw tickets over the wall to QA" created, and it has been very, very ugly. It defies common sense how culture around tools and processes for dev and ops roles continues to evolve over time, but for some reason testers are still trying to test software off in a silo, like it's released once or twice a year on CD-ROM.

I also have concerns about said junior developers wielding such tools, because yes, without being able to supply the right kind of context and being able to understand the difference between a good solution and a bad solution, they will produce tons of awful, but technically working code.

Topics like DEI have definitely become a much more touchy subject in the last 2 years or so, and that they are not discussed as much in "official" channels as they previously were, but that the practices are mostly still there and are generally still considered a positive thing to most people.

It might just be semantics, but I do think your definition of melting pot is slightly off, in that in the US, there is no real consensus of what "the same culture & set of values' actually means. The US is still a very young country. The only "native" culture here was colonized and mostly erased by white settlers. The population of people here can largely be defined by different waves of historical immigration from other parts of the world. Culture and values here are more of two-way street, where they tend to be mixed and matched in the "melting pot" type environments that have popped up all over the country. Now with that being said, most recently we have found ourselves in a situation where an extremely vocal (and quite incoherent IMHO) minority of people against rising waves of multiculturalism have come into power and started controlling the narrative, but I would say that they are not representative of most US citizens, and that the only reason why this has happened is because 90 million people were too apathetic and mentally lazy to defend against it when given the opportunity. I'm still struggling to understand what that says about the US as a people, but I really don't think that as many of us are as wrapped up in identity politics as it might seem like we are from the outside.