To answer the question in depth we first have to look at the circumstances of the charter. After William II. Rufus died on August 2nd of 1100, Henry hurried first to Winchester - to secure the royal treasure - and then to Westminster, where he was crowned king on August 5th, despite only a handful of nobles being present and both archbishops of the kingdom unavailable. This haste was necessary though because Henry's oldest brother, Robert Curthose, also had a very good claim to the throne of England, even though during this time he was still on his way back from the first crusade.
So, either on the day of his coronation or a few days after (there is no consensus on this, but for this question it can be ignored) Henry issued the charter, which was largely based on the threefold coronation oath common at the time, and had it distributed in the kingdom. It's not entirely sure if the initative to the charter came from Henry himself or if Henry was pressed by the nobles, as many of the points in the charter discussed the relation between king and nobles, especially the status of heirs and widows. In any case the charter can be seen as a token to secure Henry's reign which wasn't very stable in its first years. The charter was confirmed again by Henry when his brother Robert set sail in 1101 to gain the english throne which he laid claim on. In the end Robert could be paid off by Henry and the first rough part of his reign laid behind him.
So, why is this important? The monarchs following Henry simply had more support in the nobility than Henry had in his first years. Stephen, at least in the beginning of his reign in England, had the support of the nobles while Mathilda and Geoffrey of Anjou were busy in Normandy until 1144. In 1154 Henry II could wait six whole weeks between the death of Stephen and his own coronation because he didn't have to fear anyone taking the throne in the meantime. And Richard even had the support of the french king Philipp August, even though that friendship broke apart quite soon.
Despite this I wouldn't say that the charter was forgotten. Stephen and Henry issued coronation charters themselves, and the charter of liberties was nothing else before it became the charter of liberties (the name was applied later on). Both of them even referenced the coronation charter of Henry I, even though their charters weren't as long as Henrys. Henry II basically wrote I give you all the good laws that my grandfather Henry gave. So while the contents may have been ignored or simply not enforced, a tradition of distributing the oral coronation oath in written form seems to have taken hold in England. Henry II was later on even confronted by Thomas Becket who explicitly referred to Henry II's coronation charter.
The charter then got new gravitas when Stephen Langton used it as a blueprint for Magna Carta. This may have been caused by a rising interest in justice and law. J. C. Holt, Magna Carta, 3rd ed., Cambridge 2015, p. 25, writes on this:
[...] there were many copies of Henry I's Charter in circulation in the early years of the thirteenth century, and [...] they were studied intensively – which is what has always been apparent from the chroniclers, inaccurate though some of the details of their accounts have been judged to be.
This may be the cause why the charter comes up again more than a century later. In the events preceeding Magna Carta the charter of liberties came in handy for the barons and especially Stephen Langton.
I hope this answers your question at least partly. Feel free to ask further. I have to admit though that my strong side at the moment is the time of Henry I and not really the time of Magna Carta.
Here is some further reading.
On the Charter of Liberties:
Teunis, Henry B., The coronation charter of 1100: a postponement of decision. What did not happen in Henry I's reign, in: Journal of Medieval History 4/1 (1978), pp. 135–144.
Dalton, Paul, The Accession of King Henry I. August 1100, in: Viator 43/2 (2012), pp. 79–109.
On Henry I in general still:
Hollister, Charles Warren, Henry I (Yale English Monarchs), New Haven 2001.
On Magna Carta:
Holt, J. C., Magna Carta, 3rd ed., Cambridge 2015.
Carpenter, David, Magna Carta, London 2015.
edit: English is not my mother tongue, so please be kind.