I don't know, I think not mentioning disfellowshipped ones will just reinforce in the r&f's mind that being irregular is leaving Jehovah. It might serve to tighten the noose to those so susceptible.
I'm thinking along these lines. I haven't read it yet, but my feeling is that this brochure is primarily to harden active JWs, not to actually get anyone back. They know that in most cases if someone becomes inactive, trying to get them back will be fruitless (or at best, temporary) unless there's some major life event and in that case they're probably fairly likely to come back on their own (this is all assuming that they're still indoctrinated).
Sure, this might pull a few more poor souls back into the cult (but only if they never truly escaped) but the primary purpose is the effect it will have on those who are active. For any with inactive family it will make them think "the GB is so loving that they know how difficult this is and they're trying to help." It will also reinforce that any inactive ones have "left Jehovah" not a man-made organization, thus helping to harden the R/F's view that they're on the moral high-ground and are unassailable - essentially an indirect ad hominem argument against anything that an inactive person might say about why they left. For JWs that know some inactive ones but aren't close to them, this will only serve to increase their feelings of superiority and make them want to go on and on about Jehovah and the cult anytime they happen to bump into them - which will likely be effective in alienating any who are mentally out so that they think "why bother" instead of trying to help wake up an active JW.
Like I said, I haven't read the brochure so correct me if I'm wrong, but I'm guessing there's also a few "examples" of why someone might've left - yes? These are there to further reinforce the idea that there is no valid reason to leave - the examples will probably be things like materialism, fornication, the anxieties of life, depression, a perceived (never real!) injustice that they've suffered, etc. This will cause the readers to look back over past interactions with the inactive person they're considering and re-interpret them through this lens. Did you buy a new car a little while after you left? You're materialistic and probably a workaholic - you're just too selfish to give time to Jehovah. Did you claim depression during your fade? You've become bogged down by the anxieties of life and not putting enough trust in Jehovah. Did you get reproved/DF'd before leaving with no attempt to come back? You feel like Jehovah's attempts to help you were unjust and you are therefore "puffed up with pride" and won't come back. etc. etc. The human brain is amazing at fitting things to patterns (even when they're not there) and when they list reasons why someone might leave the brain's inclination is to automatically make their observations fit the pattern. Sort of a retro-active confirmation bias.
To me this seems more like damage control than any real effort to draw anyone back. Threre's a complex set of emotions that an active JW goes through when someone close to them leaves. There's saddness, guilt, confusion, etc. and in that the mind will often wander - this gets out in front of anyone's mind wandering to things like "what if they have a valid reason?" or "what if they left because they know something about xxx" where xxx is a doubt that they have themselves. Putting the R/F on the moral high-ground (in their minds) will harden their resolve to stay.
