Hi there,
I think you’ve answered your first question yourselves – if the website is only showing flights up to June, then they open their flights up to nine months in advance. That’s an improvement on previous years, when six months was the limit.
On the whole, it’s almost always worthwhile flying into Madagascar with Air Mad on account of the discount on domestic flights.
From Paris, Air Mad is nowadays usually the cheapest option. As #1 noted, they’re cheaper than Air France at the moment. The other Paris option, Corsair , often charges less for the long-haul flight, but flies from Orly, not CDG. By the time you’ve taken into account the cost of transferring to Orly, one or more nights in a hotel because of Corsair’s less than ideal flight schedules and having to pay the full price for your domestic flights, Air Mad usually wins out again by a long way.
As #1 also noted, you don’t have to fly from CDG to get the discount. In your first post, you said your starting point was London. Other posters have reported getting a good deal from London to Mauritius with Air Mauritius. You could continue from there with Air Mad and have a discount on domestic flights.
Another option would be to check out what kind of deal you can get on a flight to Nairobi (or Johannesburg as #1 mentioned) and continue from there with Air Mad.
In case you might have time between landing in Tana and continuing, you might also find my comments here on the forum concerning buying domestic tickets in Madagascar itself useful.