Alright, I've probed every last depth of the internet to find the answer to this thing and the best evidence I've come up with is this.
What seems to be the case is that either Facebook has glitched itself out or they have issued a limited release of this function in certain countries (India) as some form of beta testing. Thus far no mainstream media or any other credible source apart from internet speculation as to this functions release.
However this topic seems to be picking up considerable interest, so one can assume a large number of people are affected, in which case Facebook should release a press statement either today or tomorrow or some other coverage should take place.
I will keep this answer update with any new information.
- Update 1 : May 11 2017 Update from TheDailyDot Indicates existence of
thankful emoji, but no mention to the year? and does not describe it
as a new feature. Perhaps it is recurring feature for every mothers day?
- Update 2 : May 12 2017 Update from the metro as far as it shows the thankful reaction is now being rolled out across the word to coincide with the American Mothers Day which falls on the 14th of May
. It can be used throughout this weekend as a normal reaction but will disappear afterwards. The Stack Exchange network simply noticed this phenomenon hours before any major newspaper or even an official press release. Good Job Guys!!
- Update 3: May 13th 2017, Update from TechCrunch Full complement of Mothers Day features released including cards, stickers, masks, filters etc.
IMPORTANT SIDE NOTE: I personally have not observed this phenomenon on my own Facebook, and only seen such reactions appearing on certain friends from certain countries. I therefore conclude this roll-out is limited to countries who celebrate mothers day on the 2nd Sunday of May.
Below is a list of countries that celebrate Mothers day on this day. If you do not reside in these countries you may not see this feature on your Facebook.
Anguilla
Antigua and Barbuda
Aruba
Australia
Austria
Bahamas
Bangladesh
Barbados
Belgium
Belize
Bermuda
Bhutan
Bonaire
Botswana
Brazil
Brunei
Canada
Cambodia
Chile
China
Colombia
Croatia
Cuba
Curaçao
Cyprus
Czech Republic
Denmark
Dominica
Ecuador
Estonia
Ethiopia
Fiji
Finland
Germany
Ghana
Greece
Grenada
Guyana
Honduras
Hong Kong
Iceland
India
Italy
Jamaica
Japan
Kenya
Latvia
Liberia
Liechtenstein
Macau
Malaysia
Malta
Myanmar
Namibia
Netherlands
New Zealand
Pakistan
Papua New Guinea
Peru
Philippines
Puerto Rico
Saint Kitts and Nevis
Saint Lucia
Saint Vincent and the Grenadines
Samoa
Singapore
Sint Maarten
Slovakia
South Africa
Sri Lanka
Suriname
Switzerland
Taiwan
Tanzania
Tonga
Trinidad and Tobago
Turkey
Uganda
Ukraine
United States
Uruguay
Vietnam
Venezuela
Zambia
Zimbabwe