The problem is that no letters have gone out. This is all based on a report by George Conger in the Church of England Newspaper, now stretching back to last Friday, and the link the MCU uses is to the Anglicans United news blog where the text above the heading states:
Ed. Note: YES! The letters are in the mail. (See April 6 posts) 600 of the 887 adjudicating and suffragan bishops have indicated they will attend as of April 15. Most of those who have declined are from the Global South, the most populous and fastest growing portion of the Communion. The goal of sending the letters is to encourage these bishops to attend. Please pray that Lambeth - devoid of its spiritual core - will not be irrelevant before it even begins. Cheryl M. Wetzel]
That's not what was said to Mr Conger. The report has it:
A spokesman for the Archbishop of Canterbury, Dr. Rowan Williams told The Church of England Newspaper that letters affirming support for Windsor and the Covenant process had not yet been mailed, but would go out presently.
The rest of the report is based on the Archbishop of Canterbury's Advent Letter. We do not know that these letters will reflect in a fulsome way the disciplining content for which these evangelicals hope.
No doubt letters of some intention will go out. The point is they have not, yet, still, and all they have to be about is discussing unease with the Lambeth Conference agenda. Nor does anyone see the absurdity within the process, that the letters if too strong risk denying the very sorting out that a mixed gathering at Lambeth would allow. In any case the outcome of the contents of a Covenant is not fixed, especially given the St Andrew's Draft and that such a draft with the possible appendix would not get past many Anglican Churches.
The Advent Letter was written to impress, and in itself is an appalling document of pseudo-Catholic centralisation and fundamentalist biblicism wrapped into a ball. It has not a cat in hell's chance of being the outcome of anything unless forced through by the craftiest of managers, and no chance of being taken on board by many Churches (provinces). The danger is the utter mess that becomes the outcome, that both looks like it constrains and does not constrain and leaves something in place worse than the present situation.
So what is more likely? The Archbishop of Canterbury has given us a clue today:
We don’t want at the Lambeth Conference to be creating a lot of new rules but we do obviously need to strengthen our relationships and we need to put those relationships on another footing, slightly firmer footing, where we have promised to one another that this is how we will conduct our life together. And it is in that light that at this year we are discussing together the proposal for what we are calling a covenant between the Anglican Churches of the world. A covenant. A relationship of promise. We undertake that this is how we will relate to one another; that when these problems occur, that this is how we will handle them together, that this is how advice will be given and shared and that this is how decisions and discernment can be taken forward.That is a very a big part of what we will be looking at this year but it is not everything because no covenant, no arrangement of that sort is worth the paper it is written on if it doesn’t grow out of the relationships that are built as people pray together and share their lives together over tow [sic] and a half weeks...
What I would really most like to see in this years Lambeth Conference is the sense that this is essentially a spiritual encounter. A time when people are encountering God as they encounter one another, a time when people will feel that their life of prayer and witness is being deepened and their resources are being stretched. Not a time when we are being besieged by problems that need to be solved and statements that need to be finalised, but a time when people feel that they are growing in their ministry.
In other words, even allowing for understatement, not a lot of new rules and a spiritual encounter. There may well be an outcome of adding quite a few rules, but, as seen, too many and it won't get past the Churches who have already said a no or cannot do. The danger of a mess - an outcome beyond Lambeth that is not enough to be effective, but too much of a change to be affective as was - is still very likely.