It's still fairly common to hear that autistic people "take everything literally" and "don't understand sarcasm". Through examining my own experience and observing others from various ends of the spectrum, I've come to view this as an oversimplification. I think that the instinct to read between the lines is just as present in most of us as it is in neurotypicals, and that our difficulty lies in doing it accurately.
My sister is autistic and quite severely learning disabled (childhood speech delay, mental capacity of around 6/7 years old). She seeks constant emotional reassurance, yet increasingly takes offence when we give it to her, as it's taken to imply that she isn't happy (something she resents ever admitting), when this isn't how it's intended. Even an innocuous remark about something positive that happened in the past will be misinterpreted as implying that her life isn't as good in the present. This isn't the behaviour of someone who takes spoken communication at face value, but someone who instinctively tries and fails to do the opposite.
I would even say that a significant number of high-functioning autistics I've met offline through various social groups actually have an above-average grasp of irony. Even with obvious social and communication difficulties, their approach to humour often tends to be quite dark, twisted and sarcastic.
As for me, while I do have difficulty with non-verbal communication, and there are times when the true meaning of a sarcastic comment might elude me, I definitely don't lack an instinctive understanding that language can't reliably be taken at face value. I have come across a few who genuinely do seem to lack this instinct, but my experience suggests that its prevalence is overstated.