I think the point Megatran is trying to make is that we get quite lengthy periods of time between the first reveals or announcements, to the release date of the Masterpiece toy... particularly for new moulds.
As such, we often have several new moulds known at any one time, during that lengthy period... and since we haven't had anything other than Dinobot currently known, it is unusual - but not enough to get worried about just yet.
It is also worth noting that in the last three years, there has been a 7-8 month gap between new moulds during the middle of the year.
In 2016 we didn't have a new mould from March (Shockwave) to October (Beast Convoy).
In 2015 we didn't have a new mould from March (Star Saber) to November (Tracks).
In 2014 we didn't have a new mould from March (Ratbat) to September (Wheeljack).
And so far for 2017, we had Megatron in April, but with only Dinobot being the only new mould known, and not likely to be out before the end of the year (due to no images yet), we aren't likely to have any new moulds before October, but if there is, it needs to be revealed very soon. (the shortest period between reveal and release for a new mould is 5 months, for Hot Rodimus)
Some stats for those loving all the graphs...
From 2014 to 2017 - there were 35 JP & HK Masterpiece toys that were not reissues, or released by other businesses (BAPE). It also doesn't include Dinobot, because the release date is not yet known.
2014 - 8 (3 new moulds, 2 modified moulds, 3 redecos)
2015 - 9 (2 new, 2 modified, 5 redecos)
2016 - 12 (5 new, 2, modified, 5 redecos)
2017 - 6 to June (2 new, 2 modified, 2 redecos)
(so far, 2017 is keeping up with the recent prolific rate, and only needs two more for the last 6 months to equal the previous movie year of 2014)
Period of time between first announcement/reveal to release...
New mould (12 toys) - 8.6 months
Modified mould (8 toys) - 6.5 months
Redeco (15 toys) - 4.4 months
Going by the averages, the odds that another new mould will come out in 2017, is getting very remote now (with just 8 months left in the year)... while a modified mould is also getting less and less likely too.
My guess is that for the rest of 2017, we will see 1 or 2 modified moulds and maybe 3 redecos... with Dinobot coming out in early 2018 (because we haven't even seen a grey-scale prototype yet).
The raw numbers for all of the number stats above can be posted up if requested. I just didn't want to pad out this post... and it would have taken me a lot longer to post this.