@knittingaddict
If those connotations are indeed the case in the USA then I can understand why there is a need for change.
Thing is - the overwhelming majority of people in the UK wouldn't have a clue about any of that, because our culture is totally different. Here, the term 'uncle' is used as an endearment for much-loved friends as well as family, and most people who habitually wear a bow tie are generally viewed as well-off. The connotations are pretty much the opposite in fact.
Two countries divided by a common language.
Oh come on, the UK is swamped in US culture. Haven't people seen films and series with black slaves in? Never seen a single documentary about black slavery? Maybe you're right and the vast majority have no clue about this, but a 5 minute Google and there you are, educated.
To be fair, I think pretty much every adult in the UK is well aware of the Atlantic slave trade and the consequences thereof, to a greater or lesser extent. Movements such as BLM, and a number of excellent writers and broadcasters have done a lot to help increase understanding and I think more and more, many people generally want to understand. Of course there are committed 'all lives matter' types and racists but I think many people who do not have these sorts of views are getting engaged in wanting a fair society.
However, I wouldn't expect most people in the UK to know details such as the significance of a bowtie or the word 'uncle' in this context necessarily, no. People can't be expected to think of and google everything and this is where discussion comes in, filling the gaps. I have just tried googling the bow tie and while I got a lot of really interesting material about quilt codes, there wasn't a clear explanation about a bow tie being worn by somebody in a position of servitude. Point being, it is easy to say 'just Google everything' but it isn't as simple as that.
Sometimes, as PP says, when a culture makes very different (or no) associations with (eg) a word, people would need to have their attention drawn to the fact that it is problematic in context.