No I didn't.
OK.
I inferred that Papias thought Matthew wrote a sayings gospel in Hebrew, not a narrative in Greek.
OK.
So what? You are still inferring facts not in evidence.
So let's see if there is any evidence. The above article by Lightfoot also describes how Papias believed in a literal 1000 year reign of Christ in the future, on earth. Lightfoot cites Irenaeus, Against Heresies, book 5, ch. 33. Irenaeus quotes Matthew 26:29 among other scriptures and says that "these things Papias witnesseth in writing in his fourth book". If Papias quoted Matthew 26:29, which is a saying from the last supper, with wording that is distinct to Matthew, then he must have known Matthew's gospel and the context for that saying (the last supper) within it.
We will also find evidence that the oracles of the Lord that Papias says Matthew wrote down, must include narrative, by the fact that Jesus's sayings in Greek Matthew* emerge out of the course of events in the narrative. For example, Mt 12:46 says,
While he yet talked to the people, behold, his mother and his brethren stood without, desiring to speak with him. 47Then one said unto him, Behold, thy mother and thy brethren stand without, desiring to speak with thee. 48But he answered and said unto him that told him, Who is my mother? and who are my brethren? 49And he stretched forth his hand toward his disciples, and said, Behold my mother and my brethren! 50For whosoever shall do the will of my Father which is in heaven, the same is my brother, and sister, and mother.
King James Bible
* That Papias knew Greek Matthew is shown by the way he says that "each translated (past tense) the sayings as he was able", not "translates"; here the past tense shows that it was no longer necessary for each person to translate the Hebrew, which must mean that a Greek translation had been accepted at that point
Papias' book was called, 'Exposition of Oracles of the Lord'. That Papias meant the written gospels is suggested in his preface where he says, "But I will not scruple also to give a place for you
along with my interpretations to everything that I learnt carefully and remembered carefully in time past from the elders, guaranteeing their truth."
"Along with my interpretations" suggests that he is expounding written work, and supporting this exposition with oral tradition he has received from the Elders.
It's difficult not to think of this written work as being the four gospels as we know them.