The GIF sharing feature is enabled by default for some users on WhatsApp for iOS 2.16.13 (AppStore official version!).
If you haven't the GIF feature enabled by default, try re-installing WhatsApp to enable GIFs (make a backup before).
WhatsApp is slowly enabling GIFs now (for Android stable is incoming too).

To verify if the GIF sharing feature is enabled for you, paste this GIF link in WhatsApp:
http://static1.squarespace.com/static/552a5cc4e4b059a56a050501/565f6b57e4b0d9b44ab87107/566024f5e4b0354e5b79dd24/1449141991793/NYCGifathon12.gif

Finally I have this working!
Updating to WhatsApp beta for iOS 2.16.15.22, WhatsApp will optimizing the following elements:
• Identifier of contacts
• Mentions for vCards
• Trusted contacts (probably for Business)
• Better management for WhatsApp IDs.

WhatsApp for iOS 2.16.14 is available on AppStore now.

Official changelog:
• Fixed bug where app icon sometimes doesn't show the number of unread messages.
• If you are still experiencing issues with notification sounds, please update to iOS 10.1.

New WhatsApp changelog released!

WhatsApp Messenger (iOS)
Version: 2.16.15.79
#BETA
https://itunes.apple.com/us/app/whatsapp-messenger/id310633997?mt=8&uo=4

What's new (@WABetaInfo changelog):
• Bug fixes.
• Updated Arabic, Catalan, Czech, Danish, German, Greek, English, Spanish, Finnish, French, Hebrew, Hindi, Croatian, Hungarian, Indonesian, Italian, Japanese, Korean, Malay, Norwegian, Dutch, Polish, Portuguese, Romanian, Russian, Slovak, Swedish, Thai, Turkish, Ukrainian, Vietnamese, Simplified and Traditional Chinese localizations.
• Deleted some references about iOS 6 (that seems still supported).
• WhatsApp 2.16.15.79 is compilated using the iOS 10.1 SDK.
• Some improvements to manage the cache.
• Improvements for video calls.

New hidden contact selector in latest WhatsApp beta for Android

When a user shares many contacts, the recipient can view all shared contacts using that button

You can see all selected contacts before to send

New WhatsApp changelog released!

WhatsApp Messenger (iOS)
Version: 2.16.15.105
#BETA
https://itunes.apple.com/us/app/whatsapp-messenger/id310633997?mt=8&uo=4

What's new (@WABetaInfo changelog):
• Bug fixes.
• Updated Arabic, Catalan, Czech, Danish, German, English, Spanish, Finnish, French, Hebrew, Hindi, Croatian, Hungarian, Italian, Norwegian, Dutch, Polish, Portuguese, Romanian, Russian, Slovak, Thai, Turkish and Ukrainian localizations.
• Added again iOS 6 references that WhatsApp deleted in the 2.16.15.79 beta.
• Very small improvements for Broadcast Lists (iOS 7+),

Video calls are officially enabled now in Android beta web versions (tested on 2.16.330 web).
https://www.whatsapp.com/android/

WhatsApp beta for Android 2.16.333 (ONLY): when you mute a video call, the microphone icon will appear in the PiP window.

WhatsApp enabled video calls now also for 2.16.326 and 2.16.328 web beta!
A similar behavior happened with GIF activation some weeks ago (that I also announced here on Telegram).

3 other news about WhatsApp for iOS and Android are coming in next hours.

New WhatsApp changelog released!

WhatsApp Messenger (Android)
Version: 2.16.333
#BETA
https://play.google.com/store/apps/details?id=com.whatsapp

What's new (@WABetaInfo changelog):
• Updated Updated Albanian, Arabic, Azerbaijani, Bengali, Brazilian Portuguese, Bulgarian, Chinese, Dutch, English, Estonian, European Portuguese, Finnish, French, German, Greek, Hebrew, Hindi, Italian, Japanese, Latvian, Lithuanian, Kazakh, Korean, Macedonian, Malay, Malayalam, Marathi, Panjabi, Polish, Romanian, Russian, Serbian, Slovenian, Spanish, Swahili, Swedish, Thai, Turkish, Ukrainian, Uzbek and Vietnamese localizations.
• Added new contacts selector (HIDDEN).
• Added the microphone icon in the PiP window when it is muted.
• Optimized 664 emojis.
• Optimized 115 icons.
• Bugfixes.
• This version will expire on Sat Dec 17, 2016.

New WhatsApp changelog released!

WhatsApp Messenger (Android)
Version: 2.16.334
#BETA
https://play.google.com/store/apps/details?id=com.whatsapp

• Removed the microphone icon in the PiP window when it is muted.
• Optimized 760 emojis.
• Optimized 129 icons.
• Bugfixes.
• This version will expire on Sat Dec 17, 2016.

NOTES:
Recent WhatsApp beta for Android builds haven't so much news.
When this happens, WhatsApp developers are internally working on special features that will be available in next versions.

WhatsApp video calls statistics in real time (iOS and Android - hidden).
You can also notice the MIC icon in the PiP window in the iOS screenshot (I published this news for Android some hours ago).

@WABetaInfo has still another surprise for Android users.
Wait until this will be ready.

WhatsApp beta for Android 2.16.334: GIF GIPHY/TENOR providers logo (hidden) unlocked by @WABetaInfo.