People may not have used the word 'triggered' until recently, but there have always been taboo topics of conversation, both generally and with specific individuals: I would say that censorship was often greater in the past than now.
I am reminded of a poem by Ogden Nash from the 1930s:
Mr. Barcalow's Breakdown
Once there was a man, and he was named Mr. Barcalow, to be exact,
And he prided himself on his tact,
And he said, One thing about an apple, it may have a worm in it, and one thing about a chimney, it may have soot in it,
But one thing about my mouth, I never put my foot in it.
Now never was Mr. Barcalow's tact so exquisite
As when he went for a visit,
Because whenever he entered a community
He inquired of his host and hostess what topics he could discuss with impunity,
So no matter beside whom he was deposited,
Why, he could talk to them without disturbing any skeletons that should have been kept closeted,
But one dire day he went to visit some friends,
And he started asking tactful questions about untactful conversational trends,
And his host said that here was one place that Mr. Barcalow wouldn't need his tact,
Because taboos and skeletons were what everybody there lacked,
And his hostess said, That's right, but you'd better not mention bathrooms to Emily, who you will sit by at lunch,
Because her grandmother was scalded to death in the shower shortly after complaining that there was no kick in the punch,
And his host said, Oh yes, and steer away from education when you talk to the Senator,
Because somebody said his seventeen-year-old nephew would have to burn down the schoolhouse to get out of the third grade and his nephew overheard them and did burn down the schoolhouse, including the music teacher and the janitor,
And his hostess said, Oh yes, and if you talk about love and marriage to Mrs. Musker don't be surprised her eye sort of wanders,
Because her daughter is the one who had the divorce suit with thirty-seven co-responders,
And his host said, Oh yes, and you'd better know that the war is Florence's mania,
Because her cousin-in-law was the man who sank the Lusitania,
And Mr. Barcalow said, Well, can I talk about sports
And his hostess said, Well maybe you'd better not because Louise's sister, the queer one, was asked to resign from the club because she went out to play moonlight tennis in shorts, and Mr. Barcalow said That's not so terrible is it, everybody wears shorts and his hostess said, Yes, but she forgot the shorts,
So Mr. Barcalow said Well then, what about the weather,
And his host said Well, that's what we used to discuss when we got together,
But it has recently become a pleasure we must defer
Because Jane's Aunt Julia is here from California and she seems to think every remark about the weather is a personal affront to her,
So Mr. Barcalow said, The hell with you all, and went upstairs and packed,
And that was the last that was ever heard of Mr. Barcalow and his tact.